Hedera Guardian Authentication Bypass Information Disclosure

Hedera Guardian through 3.5.1 contains an authentication bypass vulnerability in the GET /api/v1/demo/registered-users endpoint that allows unauthenticated attackers to retrieve sensitive user information. Attackers can access the endpoint without providing authentication credentials to obtain usernames, Hedera DIDs, parent registry DIDs, system roles, and policy role assignments for all registered users in the system.