CVE-2026-55870

In GoCD from 13.3.0 until 26.1.0, the tool 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.

GoCD from version 16.1.0 to 26.1.0 has a vulnerability in the internal material connection test APIs. A pipeline group administrator can invoke Test Connection for source control materials outside their authorized group and potentially use credentials from those materials. It may also resolve external secrets managed by secret-management plugins.

GoCD is a continuous deliver server. From 13.1.0 until 26.1.0, the /go/api/support/process_list endpoint does not enforce its intended administrator-only authorization. An authenticated internal user can query the endpoint while source control child processes are running and view command-line arguments, usernames, remote material URLs, and internal material paths for materials the user cannot otherwise access. Exploitation depends on unpredictable process timing, and credentials, environment variables, and user-defined secrets remain masked or omitted. This issue is fixed in version 26.1.0.

The /jobStatus.json API in GoCD before version 26.1.0 does not validate that a requested server-assigned job ID belongs to the pipeline and stage named in the request. An authenticated user can guess job IDs and retrieve status for jobs in pipelines they cannot view, including job names, state, timestamps, agent IP addresses, and associated stages.

In GoCD from 12.3.1 until 26.1.0, legacy routes under /go/admin/restful/* expose historical full server configuration to pipeline group administrators instead of restricting responses to the groups they administer. The disclosed configuration can include agent auto-registration keys, webhook invocation keys, encrypted material credentials, and GoCD administrator lists.

GoCD from 18.3.0 until 26.1.0 generates 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.

In GoCD from 18.7.0 until 26.1.0, the Get Template Config API compares HTTP method names case-sensitively when selecting authorization filters. A lower-privileged authenticated user can send a request with nonstandard HTTP method capitalization to retrieve a pipeline template by name without the required view permission and read its configuration.