FeatherPanel before 1.3.7.10 Privilege Escalation via Subuser Permission Update

FeatherPanel versions before 1.3.7.10 fail to validate permissions in the SubuserController updateSubuser handler, allowing authenticated subusers to modify their own permission records. A subuser with minimal permissions can send a crafted request to grant themselves full server control, enabling unauthorized access to sensitive data, backups, and server configuration.