CVE-2026-79537
Description
AI Translation Available
metatool-ai MetaMCP through 2.4.22 contains an insecure direct object reference (IDOR) in the MCP transport session dispatch. The session store (getSession in session-lifetime-manager.ts) is keyed only by the client-supplied mcp-session-id header with no owner, namespace, or endpoint binding, and the per-endpoint authorization middleware validates only the URL endpoint's owner, never the session. An attacker who supplies another tenant's session id ' obtained without authentication from GET /metamcp/health/sessions, which discloses active session IDs and namespace UUIDs ' can list and execute the victim tenant's private MCP tools and exfiltrate their data using the victim's forwarded credentials.
https://github.com/metatool-ai/metamcp
https://www.traceforce.ai/security-advisories/cve-2026-79537