CVE-2026-61560

@zereight/mcp-gitlab's unauthenticated arbitrary file read via `upload_markdown` enables PAT exfiltration and full account takeover

`@zereight/mcp-gitlab` is a Model Context Protocol server for GitLab. Prior to version 2.1.27, the SSE transport mode (`SSE=true`) exposes all MCP tools without any authentication. The `upload_markdown` tool reads arbitrary files from the server's local filesystem via an unsanitized `file_path` parameter and uploads them to a GitLab project. Combined, any unauthenticated network-reachable attacker can read `/proc/self/environ` to steal the server's `GITLAB_PERSONAL_ACCESS_TOKEN` and achieve full GitLab account takeover. This is the default configuration for Docker deployments. Version 2.1.27 contains a patch.

Affected

zereight · gitlab-mcp

CVSS v3.1 GITHUB

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

2.90% chance of exploitation in the next 30 days, 87th percentile

Nuclei

critical · CWE-22

Published

2026-09-15

Updated

2026-09-16

Proof-of-concept exploits (1)

• advisories/GHSA-cv3r-c5h8-f4g5

Nuclei templates (1)

• projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-61560.yaml

References

• CVE Record
• NVD entry