Jumpserver is a popular open source bastion host, and Koko is a Jumpserver component that is the Go version of coco, refactoring coco's SSH/SFTP service and Web Terminal service. Prior to version 2.28.8, using illegal tokens to connect to a Kubernetes cluster through Koko can result in the execution of dangerous commands that may disrupt the Koko container environment and affect normal usage. The vulnerability has been fixed in v2.28.8.