CVE-2026-55604: @arikusi/deepseek-mcp-server has an Authorization Bypass Through User-Controlled Key

August 25, 2026

The process-global SessionStore accepts caller-supplied session_id values without binding them to any authenticated principal or transport session. An attacker can enumerate active session IDs via deepseek_sessions, then reuse a victim-controlled session_id in deepseek_chat to retrieve and continue the victim’s conversation context.

References

github.com/advisories/GHSA-fh3r-g96v-f578
github.com/arikusi/deepseek-mcp-server/releases/tag/v1.7.0
github.com/arikusi/deepseek-mcp-server/security/advisories/GHSA-fh3r-g96v-f578
nvd.nist.gov/vuln/detail/CVE-2026-55604

Code Behaviors & Features

Detect and mitigate CVE-2026-55604 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →