phpMyFAQ is an open source FAQ web application. Versions 4.0.14 and 4.0.15 have a stored cross-site scripting (XSS) vulnerability that allows an attacker to execute arbitrary JavaScript in an administrator’s browser by registering a user whose display name contains HTML entities. When an administrator views the admin user list, the payload is decoded server-side and rendered without escaping, resulting in script execution in the admin context. Version 4.0.16 contains a patch for the issue.