What is the CVSS score of CVE-2025-64166?

CVE-2025-64166 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Mercurius are affected by CVE-2025-64166?

Organizations using Mercurius should be aware of moderate risk from CVE-2025-64166, a cross-site request forgery vulnerability rated CVSS 5.4.. A patch is available.

How to fix or mitigate CVE-2025-64166?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify anti-CSRF tokens are enforced.

Mercurius CVE-2025-64166

MEDIUM

Cross-Site Request Forgery (CSRF) (CWE-352)

2026-03-05 security-advisories@github.com

GHSA-v66j-6wwf-jc57

CSRF Mercurius

5.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.4 MEDIUM

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

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

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 05, 2026 - 16:16 nvd

MEDIUM 5.4

DescriptionGitHub Advisory

Mercurius is a GraphQL adapter for Fastify. Prior to version 16.4.0, a cross-site request forgery (CSRF) vulnerability was identified. The issue arises from incorrect parsing of the Content-Type header in requests. Specifically, requests with Content-Type values such as application/x-www-form-urlencoded, multipart/form-data, or text/plain could be misinterpreted as application/json. This misinterpretation bypasses the preflight checks performed by the fetch() API, potentially allowing unauthorized actions to be performed on behalf of an authenticated user. This issue has been patched in version 16.4.0.

AnalysisAI

Technical ContextAI

This vulnerability (CWE-352: Cross-Site Request Forgery (CSRF)) affects Mercurius is a GraphQL adapter for Fastify.. Mercurius is a GraphQL adapter for Fastify. Prior to version 16.4.0, a cross-site request forgery (CSRF) vulnerability was identified. The issue arises from incorrect parsing of the Content-Type header in requests. Specifically, requests with Content-Type values such as application/x-www-form-urlencoded, multipart/form-data, or text/plain could be misinterpreted as application/json. This misinterpretation bypasses the preflight checks performed by the fetch() API, potentially allowing unauthoriz