GoCD is a continuous deliver server. From 13.3.0 until 26.1.0, GoCD does not correctly encode and escape malicious material modification comments that mimic the special trackback format used by package materials when rendering the Stage Detail, Job/Build Detail, Value Stream Map, and Pipeline History views. A user with write access to a material tracked by GoCD can store arbitrary HTML or JavaScript in a forged package material comment, which executes in the browser session of a user who later views an affected page. Exploitation requires a victim to view a page that renders the malicious modification, and GoCD does not render every material comment in every view. Successful exploitation can expose a privileged user session or allow changes using the victim's credentials and privileges. This issue is fixed in version 26.1.0.