Jellyfin Possible Remote Code Execution via custom FFmpeg binary

Jellyfin is a system for managing and streaming media. Prior to version 10.8.13, the `/System/MediaEncoder/Path` endpoint executes an arbitrary file using `ProcessStartInfo` via the `ValidateVersion` function. A malicious administrator can setup a network share and supply a UNC path to `/System/MediaEncoder/Path` which points to an executable on the network share, causing Jellyfin server to run the executable in the local context. The endpoint was removed in version 10.8.13.