GoCD is vulnerable to historical server configuration API authorization bypass

GoCD is a continuous deliver server. 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 configuration for groups they administer. The disclosed configuration can include agent auto-registration keys, webhook invocation keys, encrypted material credentials, and GoCD administrator lists. A malicious pipeline group administrator can use disclosed agent registration data to connect a rogue compatible agent, which can create a higher-complexity path to receiving work or overwriting artifacts associated with other groups. Normal authenticated users are not affected, the endpoint does not modify server configuration, and deployments that restrict pipeline editing to full administrators or configuration repositories are not affected. This issue is fixed in version 26.1.0.