{"id":"CVE-2026-79537","state":"PUBLISHED","title":"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-mana","description":"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.","publishedAt":"2026-09-29T00:00:00.000Z","updatedAt":"2026-09-30T16:45:37.445Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"CISA-ADP"},"assigner":"mitre","products":["n/a n/a"],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":["https://github.com/metatool-ai/metamcp","https://www.traceforce.ai/security-advisories/cve-2026-79537"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/79xxx/CVE-2026-79537.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-79537","state":"PUBLISHED","datePublished":"2026-09-29T00:00:00.000Z","dateUpdated":"2026-09-30T16:45:37.445Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-08-25T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://github.com/metatool-ai/metamcp"},{"url":"https://www.traceforce.ai/security-advisories/cve-2026-79537"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-09-29T19:17:20.089Z"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.1,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-30T16:44:55.325385Z","id":"CVE-2026-79537","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","type":"CWE","lang":"en","description":"CWE-639 Authorization Bypass Through User-Controlled Key"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-30T16:45:37.445Z"}}]}}}