Vulnerability in gitpython (CVE-2026-87818)
Summary
Vulnerability in gitpython (CVE-2026-87818). Confidential information can be exposed externally.
Original description
The description as published by the source.
Summary
GitPython 3.1.59 blocks a previously available local-file read path through unsafe git diff options such as -O/--orderfile.
However, the high-level diff API still permits --no-index with the default allow_unsafe_options=False.
--no-index changes the semantics of the paths arguments: instead of repository-relative pathspecs, Git interprets them as arbitrary filesystem paths.
When combined with the still-allowed -I/--ignore-matching-lines option, this creates a content-dependent Boolean oracle over a caller-selected local file.
This was reproduced against the published GitPython 3.1.59 wheel.
The original unsafe-option path is blocked in 3.1.59, while this alternate path remains reachable without setting allow_unsafe_options=True.
Details
Confirmed API surface:
repo.index.diff(
None,
no_index=True,
I=pattern,
paths=[baseline_path, target_path],
create_patch=True,
)
The relevant behavior is:
- --no-index makes the two values supplied via paths filesystem operands rather than repository pathspecs.
- -I/--ignore-matching-lines makes Git's result depend on whether the supplied regular expression matches the relevant file content.
- GitPython exposes the resulting bit through distinguishable behavior:
- matching condition: normal return with an empty DiffIndex
- non-matching condition: GitCommandError with exit status 1
An application that forwards attacker-influenced diff options and paths and exposes the success/error distin…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-87818 has been found in gitpython.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "gitpython CVE-2026-87818" on the vendor's site.
CVE-2026-87818 (gitpython) — CWE-88 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-88) exists in gitpython.
Check the vendor advisory for the affected versions of gitpython.
Severity: Medium (CVSS 6.5/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'gitpython' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'gitpython' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
gitpythonを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web vulncheck.com
- web github.com
- web github.com
- web github.com
- web github.com