mcp‑gitlab contains a path traversal flaw in the job_id parameter of its build/index.js module. By submitting crafted values such as ../../../user, an attacker can strip the intended path prefix and redirect GitLab API requests to any endpoint that the operator’s personal access token permits. This effectively granting unauthorized API access across the instance. The weakness is a CWE‑73 path‑traversal flaw that lets an attacker manipulate the proxied request path.

This vulnerability affects installations of zereight mcp‑gitlab that include the vulnerable build/index.js implementation. The specific product version is not disclosed, so any deployment that has not yet been patched may be susceptible.

The CVSS score of 9.2 indicates a high severity vulnerability, while the EPSS score of less than 1% suggests that exploitation is currently unlikely in the general population. The vulnerability is not listed in the CISA KEV catalog. Attackers can exploit the flaw via remote HTTP requests to the job_id endpoint, provided they possess a valid operator personal access token with sufficient permissions. No additional networking or configuration prerequisites are listed; the existence of a suitable token is the sole requirement for exploitation.