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CVE-2026-30241GHSA-M4H2-MJFM-MP55

Mercurius: queryDepth limit bypassed for WebSocket subscriptions

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 16.8.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • mercurius-js mercurius

    fixed in 16.8.0

  • mercuriusnpm

    fixed in 16.8.0

References 2

GitHub · mercurius-js/mercurius