- Revised the kubelet API Authorization with new subresources, that allow finer-grained authorization checks and access control for kubelet endpoints.
  Provided you enable the `KubeletFineGrainedAuthz` feature gate, you can access kubelet's `/healthz` endpoint by granting the caller `nodes/helathz` permission in RBAC.

- The `system:aggregate-to-edit` role no longer includes write access to the Endpoints API. For new Kubernetes 1.22 clusters, the `edit` and `admin` roles will no longer include that access in newly created Kubernetes 1.22 clusters. This will have no affect on existing clusters upgrading to Kubernetes 1.22. To retain write access to Endpoints in the aggregated `edit` and `admin` roles for newly created 1.22 clusters, refer to https://github.co...

functions, and on making security functions more understandable for users.

RBAC [cluster role aggregation](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#aggregated-clusterroles), introduced in 1.9, graduated to stable status with no changes in 1.11, and [client-go credential plugins](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#client-go-credential-plugins)  graduated to beta status, while also adding support for obtaining TLS credentials from an external...

* Fix cluster autoscaler addon permissions so it can access batch/job. ([#69858](https://github.com/kubernetes/kubernetes/pull/69858), [@losipiuk](https://github.com/losipiuk))

### (No, really, you MUST read this before you upgrade)

- kube-apiserver:

* The kubelet API is now secured, only cluster admins are allowed to access it.
* Insecure access to the API Server over `localhost:8080` is now disabled.
* The control plane components now talk securely to each other. The API Server talks securely to the kubelets in the cluster.

* Fix cluster autoscaler addon permissions so it can access batch/job. ([#69858](https://github.com/kubernetes/kubernetes/pull/69858), [@losipiuk](https://github.com/losipiuk))

  - removed the ability to set `kubernetes.io`- or `k8s.io`-prefixed labels via `--node-labels`, other than the [specifically allowed labels/prefixes](https://github.com/kubernetes/enhancements/blob/master/keps/sig-auth/279-limit-node-access/README.md#proposal). ([#79305](https://github.com/kubernetes/kubernetes/pull/79305), [@paivagustavo](https://github.com/paivagustavo))

- client-go

* Fix CVE-2019-11249: Incomplete fixes for CVE-2019-1002101 and CVE-2019-11246, kubectl cp potential directory traversal ([#80436](https://github.com/kubernetes/kubernetes/pull/80436))
* Fix CVE-2019-11247: API server allows access to custom resources via wrong scope ([#80750](https://github.com/kubernetes/kubernetes/pull/80750))

  - [Changelog since v1.20.10](#changelog-since-v12010)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access](#cve-2021-25741-symlink-exchange-can-allow-host-filesystem-access)
  - [Changes by Kind](#changes-by-kind-4)
    - [Bug or Regression](#bug-or-regression-4)
    - [Other (Cleanup or Flake)](#other-cleanup-or-flake-1)
  - [Dependencies](#dependencies-4)