The Frontend File Manager Plugin plugin for WordPress is vulnerable to Authenticated Arbitrary File Deletion in versions up to and including 23.6. This is due to a case-sensitive bypass of the wpfm_dir_path parameter sanitization in the wpfm_file_meta_update AJAX handler, where supplying WPFM_DIR_PATH in uppercase evades the unset check and is normalized to wpfm_dir_path by sanitize_key() during update_post_meta(), allowing an attacker to overwrite the stored file path with an arbitrary filesystem path that is then passed directly to unlink() in delete_file_locally() without any directory containment validation. This makes it possible for authenticated attackers with Subscriber-level access to delete arbitrary files on the server, including sensitive files such as wp-config.php, potentially leading to full site takeover.