VulnerabilityPublished 3 Sep 2026Updated 26 Oct 2026

CVE-2026-82392: pnpm · Virtual store linker path traversal via unvalidated depPath name in lockfileToDepGraph

Affects pnpm@10Source GCVE Database

Not known to be exploited · CVSS 7.1 High : upgrade to 10.34.5 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.34.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade pnpm@10 to 10.34.5.

Affected software

Product	Affected	Fixed in
Homebrewpnpm@10`pkg:brew/pnpm%4010`Other threats	Affected >=10.33.2 <10.34.5	Fixed in 10.34.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

## Summary The virtual store linker constructs package installation directories using `path.join(modules, pkgName)` where `pkgName` is extracted from lockfile `packages` keys via `dp.parse(depPath).name` without validation. A crafted `pnpm-lock.yaml` with traversal sequences in depPath keys (e.g., `../../../tmp/pwned@1.0.0`) causes package content to be written to arbitrary filesystem paths during `pnpm install`. This is an incomplete fix of GHSA-fr4h-3cph-29xv — the `safeJoinModulesDir` containment helper was applied to the hoisted linker and `symlinkDependency` but NOT to the virtual store linker's `lockfileToDepGraph.ts:233`. ## Details ### Root Cause `dp.parse()` at `pnpm11/deps/path/src/index.ts:135` extracts the package name as: ```typescript const name = dependencyPath.substring(0, sepIndex) ``` This is a raw substring operation with zero validation that `name` is a valid npm package name. A depPath of `../../../tmp/pwned@1.0.0` yields `name = '../../../tmp/pwned'`. ### Vulnerable Code Path 1. `pnpm-lock.yaml` → `lockfile.packages['../../../../../../../tmp/pwned@1.0.0']` (attacker-controlled lockfile key) 2. `nameVerFromPkgSnapshot(depPath, pkgSnapshot)` at `lockfile/utils/src/nameVerFromPkgSnapshot.ts:16` → calls `dp.parse(depPath)` → returns `{ name: '../../../../../../../tmp/pwned' }` 3. `lockfileToDepGraph.ts:232` → `modules = path.join(dirInVirtualStore, 'node_modules')` 4. `lockfileToDepGraph.ts:233` → `dir = path.join(modules, pkgName)` → resolves to `/tmp/pwned` (ESCAPES virtual store) 5. `storeController.importPackage(depNode.dir, ...)` → writes package content to the traversed path ### Why Existing Defenses Don't Catch It - **`depPathToFilename()`** — replaces `/` with `+` for the `dirInVirtualStore` path, but `pkgName` comes SEPARATELY from `dp.parse()` and is NOT passed through this function - **`verifyLockfileResolutions()`** — validates dependency map keys (aliases) via `isValidDependencyAlias()`, but never validates the depPath keys themselves - **Lockfile parser** — `yaml.load(lockfileRawContent)` with no schema validation on `packages` keys - **`importPackage()`** — accepts `targetDir` and passes it directly to `cafsStore.importPackage(targetDir, ...)` with zero containment check - **Integrity verification** — requires a real fetchable package but does not validate the destination path ### Escalation to RCE (non-default config) When `dangerouslyAllowAllBuilds: true` is configured (or the traversal package name is in the explicit `allowBuilds` list), the same traversed path is used in the rebuild phase at `after-install/src/index.ts:402,470`. The attacker's `postinstall` script then executes with the victim's shell access. Under default config, `allowBuild` returns false for unknown packages, limiting impact to arbitrary file write. ### Also Affected (PnP linker) When `nodeLinker: pnp` is configured, `lockfileToPackageRegistry()` at `lockfile/to-pnp/src/index.ts:105-110` uses the same unvalidated `dp.parse().name` in `packageLocation` construction, allowing the `.pnp.cjs` resolver map to point outside the virtual store. This is a lower-impact variant (PnP is not the default linker). ## Impact An attacker who can commit a crafted `pnpm-lock.yaml` to a repository (or supply one via a malicious package) can cause arbitrary file writes on the machine of any user who runs `pnpm install`. Written content is the actual package files from a real npm package (attacker controls which package and which destination). Targets for arbitrary file write include: - `.git/hooks/pre-commit` — code execution on next git operation - `~/.local/bin/` — binary hijacking - Project source files — supply chain injection ## Reproduction Craft a `pnpm-lock.yaml`: ```yaml lockfileVersion: '9.0' packages: ../../../../../../../tmp/pwned@1.0.0: resolution: {integrity: sha512-<real-package-integrity>} engines: {node: '>=14'} snapshots: ../../../../../../../tmp/pwned@1.0.0: {} importers: .: dependencies: legitimate-name: specifier: ^1.0.0 version: ../../../../../../../tmp/pwned@1.0.0 ``` Run `pnpm install` — package content is written to `/tmp/pwned/` instead of the virtual store. ## Recommended Fix Apply `safeJoinModulesDir` (or equivalent validation) at: - `lockfileToDepGraph.ts:233` — `path.join(modules, pkgName)` - `after-install/src/index.ts:402` — `path.join(pkgModulesDir(depPath), pkgInfo.name)` - `lockfile/to-pnp/src/index.ts:105-110` — PnP `packageLocation` Alternatively, validate depPath keys during lockfile parsing to reject any that don't produce valid npm package names via `dp.parse()`. ## Relationship to GHSA-fr4h-3cph-29xv GHSA-fr4h-3cph-29xv fixed the hoisted linker path (`lockfileToHoistedDepGraph.ts:222`) by adding `safeJoinModulesDir`. The same fix was NOT applied to the virtual store linker, which uses the identical `dp.parse().name → path.join()` pattern at `lockfileToDepGraph.ts:233`.

References

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