The .spec.externalIPs field in Kubernetes Services, initially designed for non-cloud load-balancer functionality, is now deprecated due to security vulnerabilities identified in CVE-2020-8554. This field allows specifying additional IP addresses a Service responds to, but it has inherent security risks because it assumes trust among all users. Kubernetes 1.21 already recommended disabling .spec.externalIPs, and an admission controller was introduced to enforce this. Alternatives, like manually managed LoadBalancer services or non-cloud load balancer controllers such as MetalLB, offer better security and control. MetalLB allows administrators to control IP address assignments, mitigating security concerns. The Gateway API also provides a secure solution, giving administrators control over the IP through a Gateway resource. Kubernetes 1.36 officially deprecated .spec.externalIPs and started issuing warnings about its usage. Kube-proxy support for the feature will be disabled in a future release, with full removal planned in subsequent versions. Users are encouraged to migrate away from this insecure feature.