The UpdraftPlus: WP Backup & Migration Plugin plugin for WordPress is vulnerable to PHP Object Injection in all versions from 1.23.8 to 1.24.11 via deserialization of untrusted input in the 'recursive_unserialized_replace' function. This makes it possible for unauthenticated attackers 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 PO