LearnPress < 4.1.7.2 - Unauthenticated PHP Object Injection via REST API

The LearnPress WordPress plugin before 4.1.7.2 unserialises user input in a REST API endpoint available to unauthenticated users, which could lead to PHP Object Injection when a suitable gadget is present, leadint to remote code execution (RCE). To successfully exploit this vulnerability attackers must have knowledge of the site secrets, allowing them to generate a valid hash via the wp_hash() function.