Group-Office is an enterprise customer relationship management and groupware tool. Prior to versions 6.8.119 and 25.0.20, a persistent Cross-Site Scripting (XSS) vulnerability exists in Groupoffice's tasks comment functionality, allowing attackers to execute arbitrary JavaScript by uploading an file with a crafted filename. When administrators or other users view the task containing this malicious file, the payload executes in their browser context. The application fails to sanitize image filenames before rendering them in the comment. By uploading an image with a crafted filename containing XSS payloads, attackers can steal sensitive information. Versions 6.8.119 and 25.0.20 contain a fix for the issue.