Cross-site scripting (XSS) vulnerability in the Web Action Quarantine Release feature in the WebGUI in Fortinet FortiMail before 4.3.9, 5.0.x before 5.0.8, 5.1.x before 5.1.5, and 5.2.x before 5.2.3 allows remote attackers to inject arbitrary web script or HTML via the release parameter to module/releasecontrol.