CVE-2026-61559
The server validates that the value is a well-formed URL (`new URL(dynamicApiUrl)`) but applies no allowlist or hostname restriction.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
`@zereight/mcp-gitlab` is a Model Context Protocol server for GitLab. Starting in version 0.0.1 and prior to version 2.1.27, when the environment variable `ENABLE_DYNAMIC_API_URL=true` is set, the server reads the `X-GitLab-API-URL` HTTP request header and uses it as the base URL for all outbound GitLab API calls made within that request. The server validates that the value is a well-formed URL (`new URL(dynamicApiUrl)`) but applies no allowlist or hostname restriction. The server then attaches the victim's `Private-Token` to every outbound fetch that uses the redirected URL. Any caller who can reach the HTTP transport can set `X-GitLab-API-URL` to an attacker-controlled host. The next GitLab API call the server makes delivers the victim's token to that host. Version 2.1.27 contains a patch.
- CVSS 3.1
- 9.6 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
- EPSS
- 0.27% probability · 20th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Source
- security-advisories@github.com
EPSS 0.3% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/zereight/gitlab-mcp/commit/6ffb4cc70706fd05b1ab80901676bc2998b6db6d
- https://github.com/zereight/gitlab-mcp/pull/625
- https://github.com/zereight/gitlab-mcp/releases/tag/v2.1.27
- https://github.com/zereight/gitlab-mcp/security/advisories/GHSA-2h44-8472-frjj
- https://github.com/zereight/gitlab-mcp/security/advisories/GHSA-2h44-8472-frjj
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.