The ManageWP Worker plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'MWP-Key-Name' HTTP request header in all versions up to, and including, 4.9.31. This is due to insufficient input sanitization and output escaping of attacker-controlled header values. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever an administrator visits the plugin's connection management page with debug parameters.