The Drag and Drop Multiple File Upload for Contact Form 7 plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.3.8.7 via deserialization of untrusted input from the 'dnd_upload_cf7_upload' function. This makes it possible for attackers to inject a PHP Object through a PHAR file. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on