Authlib's implementation examples for the RFC 7592 dynamic client registration management protocol omit a critical security check that binds the registration_access_token to the specific client being accessed. This omission allows an attacker possessing any valid registration_access_token and a target client_id to bypass authorization controls and read, update, or delete other clients' registrations. The vulnerability affects Authlib versions from 0.15 up to but not including 1.9.1 and is fixed in version 1.9.1.