metatool-ai MetaMCP through 2.4.22 contains an insecure direct object reference (IDOR) in…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-639.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-79537
- 2026-10-03 Alias added: GHSA-5xqq-w6xh-vwc6
References
Sources
- CVE-2026-79537 · CVE Program
- CVE-2026-79537 · NVD
- FIRST EPSS
- GHSA-5xqq-w6xh-vwc6 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences