GitPython: Arbitrary file truncation via git rev-list --output argument injection in unguarded Commit.count

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Commit.count() forwards kwargs into revlist with no checkunsafeoptions guard (the guard exists only in the sibling iteritems, commit.py:341). git rev-list --output=<path opens and truncates the target file to 0 bytes before revision parsing, so count(output='/victim') destroys/blanks an arbitrary file. Root Cause commit.py:290-291 calls self.repo.git.revlist(self.hexsha, kwargs) with no checkunsafeoptions and no allowunsafeoptions parameter. The sibling iteritems (commit.py:341) is guarded; count is not. This is a distinct, uncovered sink — GHSA-956x-8gvw-wg5v fixed itercommits/blame, not count. Impact Destroy/blank an arbitrary file at process privilege (integrity/availability). Reachability is key-control only (count uses self.hexsha, not a user ref), and the write is a 0-byte truncation (no content control), so MEDIUM. Proof of Concept Attack Chain 1. Entry: app forwards user options - commit.count(output='/victim'). Guard: none. Bypass proof: itercommits(output=) raises…

Published by the source

3 Aug 2026, 20:23 UTC

Last modified by the source

3 Aug 2026, 20:23 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-p538-c434-8v24

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-p538-c434-8v24

Advisory: GitPython: Arbitrary file truncation via git rev-list --output argument injection in unguarded Commit.count
IDs: GHSA-p538-c434-8v24
Record: https://patchnext.com/advisories/ghsa-p538-c434-8v24 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: gitpython 3.1.56. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI gitpython: affected <= 3.1.55; fixed in 3.1.56

## Suggested inspection (read-only)
- `python -m pip show gitpython`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on gitpython.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-p538-c434-8v24 (GitHub-reviewed advisory GHSA-p538-c434-8v24 lists affected ranges: PyPI gitpython >=0 <=3.1.55)

Commands are suggestions: review each one before running it.