CVE-2026-102266

The PyJWT library (Python implementation of JSON Web Token standards) is vulnerable in versions 2.13.0 through 2.14.0 due to a flaw in the HMACAlgorithm.from_jwk method. The PyJWK verification path fails to apply prepare_key validation when a trusted JWK Set contains an oct entry with an empty k ...

CVE-2026-102266 PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.fromjwk is affected because PyJWK verification path used the decoded key without applying preparekey validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As...

CVE-2026-102266 PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.fromjwk is affected because PyJWK verification path used the decoded key without applying preparekey validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As...