python-pyjwt: PyJWT: Denial of Service via processing of crafted detached JWS tokens

A flaw was found in PyJWT. A remote attacker can exploit this by supplying an arbitrarily large Base64URL payload segment when verifying detached JSON Web Signature JWS tokens using the unencoded-payload option. This forces excessive CPU work and memory allocations, leading to a Denial of Service...

EulerOS 2.0 SP12 : python-jwt (EulerOS-SA-2026-2557)

According to the versions of the python-jwt packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : 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...

GHSA-752W-5FWX-JX9F PyJWT accepts unknown `crit` header extensions

Summary 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 violates the MUST requirement in the RFC. This is t...