CVE-2026-12923: Improper Control of Filename for Include/Require Statement in PHP Program

The Youtube Showcase plugin for WordPress is vulnerable to Arbitrary Function Call in versions up to and including 4.0.3. This is due to insufficient validation of the 'path' parameter in the emd_delete_file() AJAX handler in includes/common-functions.php. The user-supplied value is passed through sanitize_text_field(), has its trailing '_PLUGIN_DIR' substring stripped, and is then invoked as a PHP function name with no arguments via `$sess_name()`. The handler is gated only by a nonce — no current_user_can() check is present — and the nonce is emitted on any front-end page that renders a form shortcode containing file fields. This makes it possible for authenticated attackers, with Subscriber-level access and above, to invoke arbitrary zero-argument PHP functions (such as phpinfo, phpversion, get_defined_vars, error_get_last), resulting in sensitive information disclosure and potential further compromise depending on the functions available in the environment.