Cleanuparr is a tool for automating the cleanup of unwanted or blocked files in Sonarr, Radarr, and supported download clients like qBittorrent. From 2.7.0 to 2.8.0, the /api/auth/login endpoint contains a logic flaw that allows unauthenticated remote attackers to enumerate valid usernames by measuring the application's response time. It appears that the hashing function, which is the most time-consuming part of the process by design, occurs as part of the VerifyPassword function. With the short circuits occurring before the hashing function, a timing differential is introduced that exposes validity to the actor. This vulnerability is fixed in 2.8.1.