@jsprismarine/client (>=0.12.2-unstable-20250320195345, <=0.14.1), @jsprismarine/prismarine (>=0.12.2-unstable-20250320195345, <=0.14.1) +1 more potentially affected by CVE-2026-107721 via fast-jwt (>=6.0.0, <=6.2.4)

fast-jwt NPM version =6.0.0, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.14.1 Source cves: CVE-2026-107721 Source advisory: GHSA-687G-22H4-J4W4...

fast-jwt clockTolerance: Infinity silently bypasses both exp and nbf validation (and persists in the verifier cache)

Summary createVerifier clockTolerance: Infinity silently bypasses both exp expiry AND nbf not-before validation. Any expired or not-yet-active token is accepted as valid. The same primitive also corrupts the verifier's internal cache so cached entries inherit infinite validity — they remain valid...

GHSA-687G-22H4-J4W4 fast-jwt clockTolerance: Infinity silently bypasses both exp and nbf validation (and persists in the verifier cache)

Summary createVerifier clockTolerance: Infinity silently bypasses both exp expiry AND nbf not-before validation. Any expired or not-yet-active token is accepted as valid. The same primitive also corrupts the verifier's internal cache so cached entries inherit infinite validity — they remain valid...

Insufficient Session Expiration

Overview fast-jwt is a Fast JSON Web Token implementation Affected versions of this package are vulnerable to Insufficient Session Expiration in src/verifier.js when the clockTimestamp, clockTolerance, or cacheTTL verifier options are set to non-finite values such as Infinity or NaN. The previous...

NPM: fast-jwt : Silent claim-validator bypass when JWT payload is a JSON array

NPM: fast-jwt : Silent claim-validator bypass when JWT payload is a JSON array vulnerability discovered by ? in WordPress Npm fast-jwt versions = 6.2.4...

@jsprismarine/client (>=0.12.2-unstable-20250320195345, <=0.14.1), @jsprismarine/prismarine (>=0.12.2-unstable-20250320195345, <=0.14.1) +1 more potentially affected by CVE-2026-107723 via fast-jwt (>=6.0.0, <=6.2.4)

fast-jwt NPM version =6.0.0, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.14.1 Source cves: CVE-2026-107723 Source advisory: SNYK:JS-FASTJWT-20825052...

GHSA-5HJW-83FP-PHQ9 fast-jwt : Silent claim-validator bypass when JWT payload is a JSON array

Summary fast-jwt's createVerifier silently skips all configured claim validators exp, nbf, iss, aud, sub, jti, nonce when a validly-signed JWT carries a JSON array as its payload instead of an object. The verifier reports success while having enforced only the signature. This breaks the library's...

@jsprismarine/client (>=0.12.2-unstable-20250320195345, <=0.14.1), @jsprismarine/prismarine (>=0.12.2-unstable-20250320195345, <=0.14.1) +1 more potentially affected by CVE-2026-107723 via fast-jwt (>=6.0.0, <=6.2.4)

fast-jwt NPM version =6.0.0, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.14.1 Source cves: CVE-2026-107723 Source advisory: OSV:GHSA-5HJW-83FP-PHQ9...

@jsprismarine/client (>=0.12.2-unstable-20250320195345, <=0.14.1), @jsprismarine/prismarine (>=0.12.2-unstable-20250320195345, <=0.14.1) +1 more potentially affected by CVE-2025-30144 +1 more via fast-jwt (>=6.0.0, <=6.2.4)

fast-jwt NPM version =6.0.0, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.12.2-unstable-20250320195345, =0.14.1 Source cves: CVE-2025-30144, CVE-2026-107723 Source advisory: GHSA-5HJW-83FP-PHQ9...

fast-jwt : Silent claim-validator bypass when JWT payload is a JSON array

Summary fast-jwt's createVerifier silently skips all configured claim validators exp, nbf, iss, aud, sub, jti, nonce when a validly-signed JWT carries a JSON array as its payload instead of an object. The verifier reports success while having enforced only the signature. This breaks the library's...

Improper Validation of Specified Type of Input

Overview fast-jwt is a Fast JSON Web Token implementation Affected versions of this package are vulnerable to Improper Validation of Specified Type of Input via the decode function in src/decoder.js, where a JWT with a JSON array as its payload passes the object type check because typeof ===...

NPM: fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery

NPM: fast-jwt treats raw public JWK JSON as an HMAC secret, enabling HS256 token forgery vulnerability discovered by ? in WordPress Npm fast-jwt versions 6.2.4...

@jsprismarine/client (>=0.13.5-unstable-20260512190500, <=0.14.1), @jsprismarine/prismarine (>=0.13.5-unstable-20260512190500, <=0.14.1) +1 more potentially affected by CVE-2026-107724 via fast-jwt (6.2.4)

fast-jwt NPM version 6.2.4 is affected by a known vulnerability. The following packages have a transitive dependency on fast-jwt and may be impacted: - @jsprismarine/client =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.14.1 Source cves:...

@jsprismarine/client (>=0.13.5-unstable-20260512190500, <=0.14.1), @jsprismarine/prismarine (>=0.13.5-unstable-20260512190500, <=0.14.1) +1 more potentially affected by CVE-2026-107724 via fast-jwt (6.2.4)

fast-jwt NPM version 6.2.4 is affected by a known vulnerability. The following packages have a transitive dependency on fast-jwt and may be impacted: - @jsprismarine/client =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.14.1 Source cves:...

@jsprismarine/client (>=0.13.5-unstable-20260512190500, <=0.14.1), @jsprismarine/prismarine (>=0.13.5-unstable-20260512190500, <=0.14.1) +1 more potentially affected by CVE-2026-107724 via fast-jwt (6.2.4)

fast-jwt NPM version 6.2.4 is affected by a known vulnerability. The following packages have a transitive dependency on fast-jwt and may be impacted: - @jsprismarine/client =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.13.5-unstable-20260512190500, =0.14.1 Source cves:...

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...

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...

Improper Verification of Cryptographic Signature

Overview fast-jwt is a Fast JSON Web Token implementation Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via performDetectPublicKeyAlgorithms and performDetectPrivateKeyAlgorithm in src/crypto.js, when a serialized asymmetric JWK or JWKS is...

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...