Authlib (v1.7.2 and below) contains a signature verification bypass vulnerability. The JsonWebSignature.deserialize_json() method accepts a JSON Serialization JWS object and returns the payload as successfully verified without checking for a signature and without requiring a cryptographic key.
https://kb.cert.org/vuls/id/762428
https://www.kb.cert.org/vuls/id/762428
https://github.com/authlib/authlib/security/advisories/GHSA-6v38-4h7w-rj9h
https://github.com/authlib/authlib/releases/tag/v1.9.0
https://github.com/authlib/authlib/pull/938
https://github.com/authlib/authlib/commit/6c11a02da8730914cea08ec195f1108a40dc6733