CVE-2026-30241

HIGH

8.2

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.

CVE Details

CVSS v3.1 Score8.2

SeverityHIGH

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published3/6/2026

Last Modified3/12/2026

Sourcenvd

Honeypot Sightings0

Affected Products

mercurius_project:mercurius

Weaknesses (CWE)

CWE-863

References

https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd830bdd6986(security-advisories@github.com)

https://github.com/mercurius-js/mercurius/security/advisories/GHSA-m4h2-mjfm-mp55(security-advisories@github.com)

IOC Correlations

No correlations recorded

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