* The webhook admission plugin now works even if the API server and the nodes are in two separate networks,for example, in GKE.
The webhook admission plugin now lets the webhook author use the DNS name of the service as the CommonName when generating the server cert for the webhook.
Action required:

- Add admission plugin that validates PodGroup resources reference an existing Workload and match the declared PodGroupTemplate spec. ([#137464](https://github.com/kubernetes/kubernetes/pull/137464), [@helayoty](https://github.com/helayoty)) [SIG API Machinery, Apps, Auth, CLI, Cloud Provider, Etcd, Node, Scheduling and Testing]

secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets`...

- Introduce v1alpha1 API for mutating admission policies, enabling extensible admission control via CEL expressions (KEP  3962: Mutating Admission Policies). To use, enable the `MutatingAdmissionPolicy` feature...

secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets`...

secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets`...

- **Admission webhooks:** Admission webhooks are in widespread use as a Kubernetes extensibility mechanism and have been available in beta since the 1.9 release. The 1.16 release marks the graduation of admission webhooks to general availability (GA).

- Replaced deprecated package `k8s.io/utils/pointer` with `k8s.io/utils/ptr` for the pod-security-admission admissiontests. ([#132742](https://github.com/kubernetes/kubernetes/pull/132742), [@PatrickLaabs](https://github.com/PatrickLaabs))

secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets`...

- The deprecated `SecurityContextDeny` admission plugin, which has been deprecated since `v1.27`, has been removed. It is recommended to use the Pod Security Admission plugin instead, which has been available since v1.25. Refer to the [Kubernetes documentation](https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#securitycontextdeny) for more information.