# CVE-2026-73621: GitPython before 3.1.56 Arbitrary File Truncation via Commit.count


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 13 Aug 2026
- **Updated:** 8 Oct 2026
- **Also known as:** CLSA-2026-1787042950, DEBIAN-CVE-2026-73621, ECHO-7b9b-6ad3-42a3, ECHO-c303-e516-5c89, GHSA-h75v-4jxv-ppxm, GHSA-p538-c434-8v24, MINI-2px2-x449-g5q4, MINI-fxhr-74qp-r93w, MINI-gfrw-rh5p-c7pp, MINI-r87m-95mc-w3gg, MINI-v9qh-jqq9-9xqw, PYSEC-2026-3950, ROOT-APP-PYPI-GHSA-p538-c434-8v24, UBUNTU-CVE-2026-73621

## What is CVE-2026-73621?

CVE-2026-73621 is a medium-severity vulnerability in gitpython-developers GitPython, published on 13 Aug 2026. 

### Official description

GitPython before 3.1.56 contains an argument injection vulnerability in the Commit.count() method, which forwards keyword arguments to 'git rev-list' without the check_unsafe_options guard present in the sibling iter_items method. An attacker who can control options passed to Commit.count (e.g., via an application that forwards a user-supplied options dict) can supply output=<path>, causing 'git rev-list --output=<path>' to open and truncate the target file to zero bytes before revision parsing. This allows destruction/blanking of an arbitrary file at the process's privilege level (no content control, 0-byte truncation).

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command)

## Which versions are affected by CVE-2026-73621?

3 open source packages ship an affected version, including gitpython and GitPython. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `gitpython` | PyPI | All versions | 3.1.56 |
| `gitpython` | PyPI | All versions | 3.1.56 |
| `GitPython` | PyPI | All versions | 3.1.56 |

Products: Gitpython Project Gitpython.

## How do I fix CVE-2026-73621?

Upgrade gitpython to 3.1.56 or later.

## Is CVE-2026-73621 being exploited?

There is no known exploitation of CVE-2026-73621 in the wild and no public exploit code.

## Other vulnerabilities in gitpython-developers GitPython

- [CVE-2023-40267](https://insights.sbomify.com/CVE-2023-40267/): GitPython vulnerable to remote code execution due to insufficient sanitization of input arguments (critical 9.8)
- [CVE-2026-78676](https://insights.sbomify.com/CVE-2026-78676/): GitPython before 3.1.59 Remote Code Execution via Config Injection (critical 9.3)
- [CVE-2026-67324](https://insights.sbomify.com/CVE-2026-67324/): GitPython 3.1.50 Authentication Bypass via Joined Short Options (critical 9.3)
- [CVE-2026-42215](https://insights.sbomify.com/CVE-2026-42215/): GitPython: Command injection via Git options bypass (high 8.8)
- [CVE-2026-87817](https://insights.sbomify.com/CVE-2026-87817/): GitPython before 3.1.60 Remote Code Execution via Git Directory Impersonation (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73621 and fix it if it is affected.

What it is: CVE-2026-73621 is a medium-severity vulnerability in gitpython-developers GitPython, published on 13 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-73621 in the wild and no public exploit code.

Affected packages and fixed versions:
- gitpython (PyPI): affected all versions; fixed in 3.1.56
- gitpython (PyPI): affected all versions; fixed in 3.1.56
- GitPython (PyPI): affected all versions; fixed in 3.1.56

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-73621/ (Markdown: https://insights.sbomify.com/CVE-2026-73621/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73621
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73621
- OSV: https://osv.dev/vulnerability/CVE-2026-73621

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73621/
Summaries are generated and may contain mistakes; the official description above is the record.