{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.4.22"
              }
            ],
            "source": "DESCRIPTION"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "32b6e9813acfc13d1013eb2452be1899d6654bb9"
            }
          ],
          "repo": "https://github.com/metatool-ai/metamcp",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mitre",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79537.json"
  },
  "details": "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.",
  "id": "CVE-2026-79537",
  "modified": "2026-10-02T03:31:04.953096447Z",
  "published": "2026-09-29T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79537.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-79537"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.traceforce.ai/security-advisories/cve-2026-79537"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/metatool-ai/metamcp"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}