CVE-2026-85626 Details

A vulnerability allowing argument injection has been identified in git-mcp-server version 2.15.1. This issue arises in the ref and object parameters of the git_log, git_diff, and git_show tools, which do not properly validate leading dashes. As a result, attackers can inject git command-line options, such as --output=, to manipulate file writing behaviors. Exploitation of this vulnerability could lead to unauthorized file writes outside the repository, targeting arbitrary paths accessible by the process.

To address this vulnerability, it is recommended to validate the ref, object, and branch parameters by rejecting values that begin with a dash or by only passing them after a '--' separator. Additionally, implementing a validation check to ensure the parameters conform to expected formats, such as valid ref or commit patterns, would help mitigate the risk. Re-enabling the rejection of unknown flags in the git argument validation process is also advised.