Vulnerability Description
Mercurius is a GraphQL adapter for Fastify. Prior to version 16.8.0, Mercurius fails to enforce the configured queryDepth limit on GraphQL subscription queries received over WebSocket connections. The depth check is correctly applied to HTTP queries and mutations, but subscription queries are parsed and executed without invoking the depth validation. This allows a remote client to submit arbitrarily deeply nested subscription queries over WebSocket, bypassing the intended depth restriction. On schemas with recursive types, this can lead to denial of service through exponential data resolution on each subscription event. This issue has been patched in version 16.8.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mercurius Project | Mercurius | < 16.8.0 |
Related Weaknesses (CWE)
References
- https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd8Patch
- https://github.com/mercurius-js/mercurius/security/advisories/GHSA-m4h2-mjfm-mp5Vendor Advisory
FAQ
What is CVE-2026-30241?
CVE-2026-30241 is a vulnerability with a CVSS score of 8.2 (HIGH). Mercurius is a GraphQL adapter for Fastify. Prior to version 16.8.0, Mercurius fails to enforce the configured queryDepth limit on GraphQL subscription queries received over WebSocket connections. The...
How severe is CVE-2026-30241?
CVE-2026-30241 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-30241?
Check the references section above for vendor advisories and patch information. Affected products include: Mercurius Project Mercurius.