CVE-2026-107724

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...

GHSA-WW5H-9M49-7XX4 fast-jwt: Incomplete patch of CVE-2026-34950: Non-whitespace key-prefix re-enables RSA→HS256 algorithm confusion

Summary The fix for CVE-2026-34950 CVSS 9.1, released in v6.2.0 is incomplete. It adds key.trim to the PEM-detection path in src/crypto.js, but String.prototype.trim only strips characters classified as whitespace by the ECMAScript specification. The subsequent ^-anchored regex /^-----BEGIN?: RSA...

CVE-2026-107724

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...

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...

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...

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...

PT-2026-108253

Name of the Vulnerable Software and Affected Versions fast-jwt version 6.2.4 Description An issue exists where raw serialized public JSON Web Key JWK or JSON Web Key Set JWKS JSON is incorrectly classified as an HMAC secret. This occurs because the performDetectPublicKeyAlgorithms function in...

CVE-2026-107724: Improper Verification of Cryptographic Signature

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...

PT-2026-108251

Name of the Vulnerable Software and Affected Versions fast-jwt versions 6.2.0 through 6.2.x Description fast-jwt can misclassify an RSA public key as an HMAC secret if the key contains non-whitespace content such as control characters, zero-width characters, comments, or wrapper text before its P...