SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-64166

Prior to version 16.4.0, a cross-site request forgery (CSRF) vulnerability was identified.

MEDIUM 5.4EPSS 0.16%

Does this matter?

Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS
0.16% probability · 5th percentile
CISA KEV
Not listed
Weakness
CWE-352
Affected
mercurius project/mercurius
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.