UTMStack < 11.2.16 Account Enumeration via Password Reset Endpoint

UTMStack before 11.2.16 contains an account enumeration vulnerability that allows unauthenticated attackers to determine registered email addresses by observing differing HTTP responses from the POST /api/account/reset-password/init endpoint. Attackers can submit arbitrary email addresses and distinguish registered accounts, which return 200 OK, from unregistered accounts, which trigger a 500 Internal Server Error with backend error details, enabling targeted phishing or credential attacks.