Cockpit CMS 2.14.0 Authenticated Command Injection via FFmpeg Filename

Cockpit CMS 2.14.0 and prior contains a command injection vulnerability in the FFmpeg integration that allows authenticated users with only the assets/upload permission to execute arbitrary commands by uploading a video file with a shell metacharacter-laden filename. The unsanitized filename is interpolated into a shell command executed via Process::fromShellCommandline() before the slugify() sanitizer runs, enabling injected shell metacharacters such as backticks, $(), and semicolons to escape the FFmpeg command context and execute as the web-server user.