The WP Simple Galleries plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.34 via deserialization of untrusted input from the 'wpsimplegallery_gallery' post meta via 'wpsgallery' shortcode. This allows authenticated attackers, with contributor-level permissions and above, to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.