HIGH 7.4 NVD
CVE-2026-102271
PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard
PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.
References
- https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773
This high severity vulnerability with a CVSS score of 7.4 was published on 2026-09-28 via NVD.
vulnfeed aggregates 13624 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.