* [beta] User-provided apiservers can be aggregated (served along with) the rest of the Kubernetes API. See [Extending the Kubernetes API with the aggregation layer](https://kubernetes.io/docs/concepts/api-extension/apiserver-aggregation/), [Configure the aggregation layer](https://kubernetes.io/docs/tasks/access-kubernetes-api/configure-aggregation-layer/), and [Setup an extension API server](https://kubernetes.io/docs/tasks/access-kubernetes-api/setup-extension-api-server/).

- The `horizontalpodautoscaling` and `clusterrole-aggregation` controllers now assume the `autoscaling/v1` and `rbac.authorization.k8s.io/v1` APIs are available. If you disable those APIs and do not want to run those controllers, exclude them by passing `--controllers=-horizontalpodautoscaling` or `--controllers=-clusterrole-aggregation` to `kube-controller-manager`. ([#117977](https://github.com/kubernetes/kubernetes/pull/117977), [@liggit...

- Fixes a regression exposed in 1.27 by kubectl switching to openapi v3 by resolving a flake in openapi v3 aggregation ([#119839](https://github.com/kubernetes/kubernetes/pull/119839), [@atiratree](https://github.com/atiratree)) [SIG API Machinery]

* Increased verbose level for local openapi aggregation logs to avoid flooding the log during normal operation ([#75781](https://github.com/kubernetes/kubernetes/pull/75781), [@roycaihw](https://github.com/roycaihw))

### API-machinery

- Increased verbose level for local openapi aggregation logs to avoid flooding the log during normal operation ([#75781](https://github.com/kubernetes/kubernetes/pull/75781), [@roycaihw](https://github.com/roycaihw))

### Feature

- The aggregation API will have alpha support for network proxy ([#87515](https://github.com/kubernetes/kubernetes/pull/87515), [@Sh4d1](https://github.com/Sh4d1)) [SIG API Machinery]

### SIG Auth

Work this cycle focused on graduating existing functions, and on making security functions more understandable for users.

* Support OpenAPI spec aggregation for kube-aggregator ([#46734](https://github.com/kubernetes/kubernetes/pull/46734), [@mbohlool](https://github.com/mbohlool))

### Auth