Group-Office is an enterprise customer relationship management and groupware tool. Prior to versions 6.8.119 and 25.0.20, a stored and blind XSS vulnerability exists in the Phone Number field of the user profile within the GroupOffice application. This allows a malicious actor to inject persistent JavaScript payloads, which are triggered in the context of another user when they view the Address Book. Successful exploitation enables actions such as forced redirects, unauthorized fetch requests, or other arbitrary JavaScript execution without user interaction. Versions 6.8.119 and 25.0.20 contain a fix for the issue.