CVE-2026-34240 jose vulnerable to untrusted JWK header key acceptance during signature verification

JOSE is a Javascript Object Signing and Encryption JOSE library. Prior to version 0.3.5+1, a vulnerability in jose could allow an unauthenticated, remote attacker to forge valid JWS/JWT tokens by using a key embedded in the JOSE header jwk. The vulnerability exists because key selection could tre...

Authlib is vulnerable to Denial of Service via Oversized JOSE Segments

Summary Authlib’s JOSE implementation accepts unbounded JWS/JWT header and signature segments. A remote attacker can craft a token whose base64url‑encoded header or signature spans hundreds of megabytes. During verification, Authlib decodes and parses the full input before it is rejected, driving...

Null pointer dereference

jwx is a Go module implementing various JWx JWA/JWE/JWK/JWS/JWT, otherwise known as JOSE technologies. Calling jws.Parse with a JSON serialized payload where the signature field is present while protected is absent can lead to a nil pointer dereference. The vulnerability can be used to crash/DOS ...