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CVE-2026-30241

CVE-2026-30241 · Mercurius: queryDepth limit bypassed for WebSocket subscriptions

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 2.7 · Low · EPSS 0.4% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • mercurius

    Versions
    • < 16.8.0: Affected

    No fix published

  • mercurius npm

    Affected ranges
    • SEMVER: < 16.8.0

    Update to 16.8.0

Original sources

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