- kube-apiserver `--admission-control-config-file` files are now validated strictly (EnableStrict). Duplicate and unknown fields in the configuration will now cause an error. ([#128013](https://github.com/kubernetes/kubernetes/pull/128013), [@seans3](https://github.com/seans3))

- The Conformance test "validates that there is no conflict between pods with same hostPort but different hostIP and protocol" now validates the connectivity to each hostPort, in addition to the functionality. ([#96627](https://github.com/kubernetes/kubernetes/pull/96627), [@aojea](https://github.com/aojea)) [SIG Scheduling and Testing]...

- Fixed bug when using kubeadm alpha certs commands with clusters using external etcd ([#85091](https://github.com/kubernetes/kubernetes/pull/85091), [@fabriziopandini](https://github.com/fabriziopandini))
- Kubeadm no longer defaults or validates the component configs of the kubelet or kube-proxy ([#79223](https://github.com/kubernetes/kubernetes/pull/79223), [@rosti](https://github.com/rosti))

- github.com/envoyproxy/go-control-plane: [v0.12.0 → v0.13.0](https://github.com/envoyproxy/go-control-plane/compare/v0.12.0...v0.13.0)
- github.com/envoyproxy/protoc-gen-validate: [v1.0.4 → v1.1.0](https://github.com/envoyproxy/protoc-gen-validate/compare/v1.0.4...v1.1.0)
- github.com/go-logfmt/logfmt: [v0.5.1 → v0.4.0](https://github.com/go-logfmt/logfmt/compare/v0.5.1...v0.4.0)

- github.com/envoyproxy/go-control-plane: [v0.13.0 → v0.13.4](https://github.com/envoyproxy/go-control-plane/compare/v0.13.0...v0.13.4)
- github.com/envoyproxy/protoc-gen-validate: [v1.1.0 → v1.2.1](https://github.com/envoyproxy/protoc-gen-validate/compare/v1.1.0...v1.2.1)
- github.com/fsnotify/fsnotify: [v1.7.0 → v1.9.0](https://github.com/fsnotify/fsnotify/compare/v1.7.0...v1.9.0)

- github.com/go-openapi/strfmt: [v0.19.3 → v0.19.5](https://github.com/go-openapi/strfmt/compare/v0.19.3...v0.19.5)
- github.com/go-openapi/validate: [v0.19.5 → v0.19.8](https://github.com/go-openapi/validate/compare/v0.19.5...v0.19.8)
- github.com/gogo/protobuf: [v1.3.1 → v1.3.2](https://github.com/gogo/protobuf/compare/v1.3.1...v1.3.2)

- `ValidateVolumeAttributesClassUpdate` also validates new VolumeAttributesClass object. ([#122449](https://github.com/kubernetes/kubernetes/pull/122449), [@carlory](https://github.com/carlory))

### Other (Cleanup or Flake)

- github.com/go-openapi/spec: [v0.19.5](https://github.com/go-openapi/spec/tree/v0.19.5)
- github.com/go-openapi/strfmt: [v0.19.5](https://github.com/go-openapi/strfmt/tree/v0.19.5)
- github.com/go-openapi/validate: [v0.19.8](https://github.com/go-openapi/validate/tree/v0.19.8)
- github.com/gobuffalo/here: [v0.6.0](https://github.com/gobuffalo/here/tree/v0.6.0)
- github.com/hpcloud/tail: [v1.0.0](https://github.com/hpcloud/tail/tree/v1.0.0)

Kubernetes supports node proxying, which allows clients of kube-apiserver to access endpoints of a Kubelet to establish connections to Pods, retrieve container logs, and more. While Kubernetes already validates the proxying address for Nodes, a bug in kube-apiserver made it possible to bypass this validation. Bypassing this validation could allow authenticated requests destined for Nodes to be redirected to the API Server through its private network.

Kubernetes supports node proxying, which allows clients of kube-apiserver to access endpoints of a Kubelet to establish connections to Pods, retrieve container logs, and more. While Kubernetes already validates the proxying address for Nodes, a bug in kube-apiserver made it possible to bypass this validation. Bypassing this validation could allow authenticated requests destined for Nodes to be redirected to the API Server through its private network.