In mcp-server-git versions prior to 2025.12.18, the gitdiff and gitcheckout functions passed user-controlled arguments directly to git CLI commands without sanitization. Flag-like values (e.g., --output=/path/to/file for git_diff) would be interpreted as command-line options rather than git refs, enabling arbitrary file overwrites. The fix adds validation that rejects arguments starting with - and verifies the argument resolves to a valid git ref via rev_parse before execution. Users are advised to update to 2025.12.18 resolve this issue.
Thank you to https://hackerone.com/yardenporat for reporting.
{
"nvd_published_at": "2025-12-17T23:16:04Z",
"severity": "MODERATE",
"cwe_ids": [
"CWE-88"
],
"github_reviewed_at": "2025-12-17T22:50:29Z",
"github_reviewed": true
}