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 CPU and memory consumption to hostile levels and enabling denial of service. Impact Attack vector: unauthenticated network attacker submits a malicious JWS/JWT. Effect: base64 decode + JSON/crypto processing of …