WWBN AVideo is an open source video platform. In versions up to and including 26.0, the "sanitizeFFmpegCommand()" function in "plugin/API/standAlone/functions.php" is designed to prevent OS command injection in ffmpeg commands by stripping dangerous shell metacharacters ("&&", ";", "|", "`", "<", ">"). However, it fails to strip "$()" (bash command substitution syntax). Since the sanitized command is executed inside a double-quoted "sh -c" context in "execAsync()", an attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server. Commit 25c8ab90269e3a01fb4cf205b40a373487f022e1 contains a patch.