GKE security is a complex challenge due to its configuration complexity and vulnerability, requiring a layered approach to protect clusters and workloads. The most critical aspects of GKE security involve authentication and authorization, control plane security, node security, and network security. CIS Benchmarks provide globally recognized best practices for implementing and managing cybersecurity mechanisms in Kubernetes, but some recommendations may not be under your control as they relate to the control plane, Kubernetes distribution, and nodes' operating system. To ensure GKE security, it is recommended to apply the principle of least privilege, use role-based access control (RBAC) to strengthen authentication and authorization, enhance control plane security, upgrade infrastructure regularly, protect node metadata, disable the Kubernetes dashboard, follow the NSA-CISA Framework, improve network security, secure pod access to Google Cloud resources, and get a GKE-configured secret manager. Additionally, using tools like CAST AI's container security module can help identify potential threats and track them efficiently.