CVE-2026-16099: Podlove Podcast Publisher <= 4.5.3 - Authenticated (Contributor+) PHP Object Injection to Arbitrary File Deletion via 'unfurl_data' Parameter

The Podlove Podcast Publisher plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the createlinkitem function in all versions up to, and including, 4.5.3. This makes it possible for authenticated attackers, with contributor-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). A viable POP chain exists within the plugin itself via Podlove\ImageCache\GenerationGuard, whose destruct() method invokes wpdeletefile() with an attacker-controlled file path populated through unserialization.