The s2Member Pro plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 241216 via deserialization of untrusted input from the 's2member_pro_remote_op' vulnerable parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. 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.