CVE-2026-61559

Critical CVSS 9.6

Published 2026-09-15 · last changed 2026-09-17

The fix

We hold no Microsoft remediation data for CVE-2026-61559, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

`@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.

Sources

NVD record for CVE-2026-61559

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N