CVE-2026-111681: EFAK through 5.1.0 Privilege Escalation via /api/users REST API

EFAK through 5.1.0 contains a missing authorization vulnerability that allows authenticated low-privilege users to manage accounts because the /api/users endpoints lack administrator role checks. Attackers can send POST, PUT, or DELETE requests to UserController to grant themselves ROLEADMIN, create administrators, or delete users, gaining control of managed Kafka clusters.