CVE-2025-64166Mercurius: Incorrect Content-Type parsing can lead to CSRF attack
Updated under an hour ago ()
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It affects mercurius-js mercurius and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 5.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- Weakness (CWE)
- CWE-352
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Mar 5, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
mercurius-js mercurius mercurius_js:mercurius (from the name) | before 16.4.0 | CNA record |
mercurius_project mercurius mercurius_project:mercurius | before 16.4.0 | NVD |
References
- https://github.com/mercurius-js/mercurius/security/advisories/GHSA-v66j-6wwf-jc57x-refsource-confirm, exploit, patch, vendor-advisory
- https://github.com/mercurius-js/mercurius/pull/1187x-refsource-misc, issue-tracking, patch
- https://github.com/mercurius-js/mercurius/commit/962d402ec7a92342f4a1b7f5f04af01776838c3cx-refsource-misc, patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.