GitPython: separate_git_dir leaks env vars via crafted .gitmodules submodule name

Exploitation

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

CVSS

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

EPSS

• CVE-2026-110855: 0.29% estimated exploitation activity in the next 30 days; percentile 21.63 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary `Repo._clone()`'s handling of `separate_git_dir` never disables `Git.polish_url()`'s environment-variable expansion, unlike every other caller of that helper that handles attacker-influenced data. Since `separate_git_dir` can be derived from an attacker-controlled `.gitmodules` submodule name, a completely ordinary `clone` + `submodule_update(init=True, recursive=True)` on a malicious repository expands an environment variable of the attacker's choosing and exposes its value both as a persistent on-disk directory name and, whenever DEBUG-level logging is enabled (a common CI/verbose-logging configuration), in a `Popen(...)` log line that is not redacted the way credential-bearing arguments are.

Root cause / Details `git/repo/base.py`'s `_clone()` has: ```python sep_dir = kwargs.get("separate_git_dir") if sep_dir: kwargs["separate_git_dir"] = Git.polish_url(sep_dir) ``` This is the only remaining `Git.polish_url()` call site handling attacker-influenced data that does…

Published by the source

27 Oct 2026, 15:26 UTC

Last modified by the source

27 Oct 2026, 15:47 UTC

Source last checked

28 Oct 2026, 06:10 UTC

1. Revision 2 · amended · 28 Oct 2026

   Amended from osv record GHSA-fx3j-rwgx-fr94

2. Revision 1 · created · 27 Oct 2026

   Published from ghsa record GHSA-fx3j-rwgx-fr94

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# Patch Next advisory brief: CVE-2026-110855

Advisory: GitPython: separate_git_dir leaks env vars via crafted .gitmodules submodule name
IDs: CVE-2026-110855, GHSA-fx3j-rwgx-fr94
Record: https://patchnext.com/advisories/ghsa-fx3j-rwgx-fr94 (revision 2, source checked 28 Oct 2026, 06:10 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: gitpython 3.2.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI gitpython: affected < 3.2.0; fixed in 3.2.0

## 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://osv.dev/vulnerability/GHSA-fx3j-rwgx-fr94 (OSV record GHSA-fx3j-rwgx-fr94 lists affected ranges: PyPI gitpython >=0 <3.2.0 (fixed))
- Verified: https://github.com/advisories/GHSA-fx3j-rwgx-fr94 (GitHub-reviewed advisory GHSA-fx3j-rwgx-fr94 lists affected ranges: PyPI gitpython >=0 <=3.1.62)

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