# CVE-2026-85626: git-mcp-server 2.15.1 Argument Injection via Git Ref Parameters

> Attackers can inject Git command-line options to write files to arbitrary paths, potentially leading to code execution or data modification.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-p58h-f635-vjjm

## What is CVE-2026-85626?

CVE-2026-85626 is a high-severity command injection vulnerability in cyanheads git-mcp-server, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

git-mcp-server 2.15.1 contains an argument injection vulnerability in the ref and object parameters of git_log, git_diff, and git_show tools that lack leading-dash validation. Attackers can inject git command-line options like --output= to write files outside the repository to arbitrary paths accessible by the process.

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

## Which versions are affected by CVE-2026-85626?


## How do I fix CVE-2026-85626?

No fix has been published for CVE-2026-85626 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-85626 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85626 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85626 and fix it if it is affected.

What it is: CVE-2026-85626 is a high-severity command injection vulnerability in cyanheads git-mcp-server, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85626 exists.

Affected product: cyanheads git-mcp-server. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-85626/ (Markdown: https://insights.sbomify.com/CVE-2026-85626/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85626
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85626
- OSV: https://osv.dev/vulnerability/CVE-2026-85626

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-85626/
Summaries are generated and may contain mistakes; the official description above is the record.