The Advanced AJAX Product Filters plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.1.9.6 via deserialization of untrusted input in the shortcode_check function within the Live Composer compatibility layer. This makes it possible for authenticated attackers, with Author-level access and above, to inject a PHP Object. 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 the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present. Note: This vulnerability requires the Live Composer plugin to also be installed and active.