fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6 Exploit, Mitigation, Vendor Advisory
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6 Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · nearformNVD modified 2026-10-24 13:10
Affected (CPE criteria) 1
cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*
References 3
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6 Exploit, Mitigation, Vendor Advisory
- https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11 Technical Description
- https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6 Exploit, Mitigation, Vendor Advisory