wpForo Forum < 3.1.6 - Subscriber+ PHP Object Injection via Profile Fields

Description

The plugin does not restrict which classes may be instantiated when it deserializes a user-supplied profile field value, allowing authenticated users with Subscriber-level access and above to inject a PHP Object.
No POP chain is present in the plugin itself; if one is present via another installed plugin or theme, this could lead to remote code execution, arbitrary file operations, or SQL injection. This is an incomplete fix of CVE-2026-49769.