GoCD is a continuous deliver server. From 18.3.0 until 26.1.0, GoCD can generate unescaped tracking-tool links from commit comments when a project uses a lenient Tracking Tool regular expression with an ID capturing group, such as JIRA-(.+). An attacker with commit access to a tracked material can place URI or HTML special characters in a matching commit comment, causing stored cross-site scripting when a victim views an affected Compare Pipeline page. Deployments without Tracking Tool integration, without an ID capturing group, or with conservative matchers that cannot match special characters are not affected. 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.