CVE-2026-102273: Pyjwt Project Pyjwt

High severity, CVSS 7.4. EPSS: 0.2% chance of exploitation in the next 30 days.

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because HMAC key guard only recognizes top-level public JWK forms and misses container representations. This occurs when an application allows HMAC and asymmetric algorithms and passes a public JWK container as the raw key. As a result, public asymmetric key material is accepted as the HMAC secret. Consequently, an attacker who knows the public key can forge a token with arbitrary authenticated claims. This issue is fixed in version 2.14.0.

Affected products

Published 2026-09-28. Last modified 2026-10-06.