What is the CVSS score of CVE-2026-30241?

CVE-2026-30241 has a CVSS 3.1 base score of 8.2 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H. EPSS exploitation probability: 0.0%.

Which versions of Mercurius are affected by CVE-2026-30241?

Mercurius GraphQL adapter versions prior to 16.8.0 fail to enforce query depth limits on WebSocket subscription connections, allowing attackers to execute resource-exhaustion attacks that could…. A patch is available.

How to fix or mitigate CVE-2026-30241?

Within 24 hours: Identify all applications using Mercurius versions prior to 16.8.0 and assess exposure. Within 7 days: Apply vendor patch to upgrade Mercurius to version 16.8.0 or later across all affected environments. Within 30 days: Conduct post-patch validation testing and review WebSocket subscription query depth configurations to ensure limits are now properly enforced.

Mercurius CVE-2026-30241

HIGH

Incorrect Authorization (CWE-863)

2026-03-06 security-advisories@github.com

GHSA-m4h2-mjfm-mp55

Denial Of Service Mercurius

8.2

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.2 HIGH

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

Patch released

Mar 12, 2026 - 15:16 nvd

Patch available

CVE Published

Mar 06, 2026 - 22:16 nvd

HIGH 8.2

DescriptionGitHub Advisory

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.

AnalysisAI

Mercurius versions prior to 16.8.0 fail to validate GraphQL subscription query depth limits over WebSocket connections, allowing remote attackers to bypass depth restrictions that are properly enforced for HTTP queries. An attacker can exploit this to submit arbitrarily nested subscription queries that cause denial of service through exponential data resolution on schemas with recursive types. A patch is available in version 16.8.0.

Technical ContextAI

Classified as CWE-863 (Incorrect Authorization). Affects Mercurius. 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 s