pyjwt: PyJWT accepts unknown `crit` header extensions (RFC 7515 §4.1.11 MUST violation)

A missing verification step has been discovered in PyJWT. PyJWT does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that PyJWT does not understand, the library accepts the token instead of rejecting it. This...

CVE-2026-35042

fast-jwt provides fast JSON Web Token JWT implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token...

CVE-2026-35042

fast-jwt provides fast JSON Web Token JWT implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token...

GHSA-HM7R-C7QW-GHP6 fast-jwt accepts unknown `crit` header extensions (RFC 7515 violation)

Summary fast-jwt does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC. ---...

PYSEC-2026-120

PyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that PyJWT does not understand, the library accepts the token instead of rejecting...

Linux Distros Unpatched Vulnerability : CVE-2026-32597

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - PyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does not validate the crit Critical Header Parameter defined in RFC 7515 4.1.11. When...

CVE-2026-32597

A missing verification step has been discovered in PyJWT. PyJWT does not validate the crit Critical Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that PyJWT does not understand, the library accepts the token instead of rejecting it. This...

PT-2026-25090

Name of the Vulnerable Software and Affected Versions PyJWT versions prior to 2.12.0 Description PyJWT is a Python implementation for handling JSON Web Tokens JWT. Before version 2.12.0, the library did not properly validate the 'crit' Critical Header Parameter as defined in RFC 7515 §4.1.11...