GHSA-G3JJ-5CMM-3HXX fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery

Summary fast-jwt 6.2.4 silently classifies raw serialized public JWK JSON as an HMAC secret. If an application supplies public JWK JSON text as the verifier key and HS256 is explicitly allowed or automatically inferred, an attacker who knows the same public JSON text can use it as an HMAC key and...

CVE-2026-107724

The fast-jwt library (version 6.2.4 ) contains a vulnerability where raw serialized public JWK or JWKS JSON can be incorrectly classified as an HMAC secret . The root cause is located in src/crypto.js within the performDetectPublicKeyAlgorithms function, which treats non-PEM strings as symmetric ...

CVE-2026-107724 fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery

fast-jwt provides fast JSON Web Token JWT implementation. In 6.2.4, fast-jwt can classify raw serialized public JWK or JWKS JSON as an HMAC secret because src/crypto.js performDetectPublicKeyAlgorithms treats non-PEM strings as symmetric key material. If HS256 is explicitly allowed or inferred, a...