Akaunting versions up to 3.1.21 contain a vulnerability that allows low-privileged authenticated users to escalate their privileges by modifying their own account to assign themselves the admin role. This occurs due to improper authorization checks in the UpdateUser job, which synchronizes user roles without verifying permissions. The API endpoints remain properly permission-gated and are not affected. The vulnerability has a high severity with a CVSS score of 8.1.