The Advanced File Manager – Ultimate File Manager for WordPress And Document Library Solution plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'soundFile' parameter in all versions up to, and including, 5.4.12 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the attacker to control a domain whose origin string is a leading prefix of the target site's backend URL (e.g. https://example.co against https://example.com), and the victim must be an authenticated WordPress administrator who visits the attacker-controlled page while the File Manager admin screen is open.