*   The default `auto-detect` behavior of the kubelet's `--cloud-provider` flag is removed.
    *   You can manually set `--cloud-provider=auto-detect`, but be aware that this behavior will be removed completely in a future version.
    *   Best practice for version 1.9 and future versions is to explicitly set a cloud-provider. See [the documentation](https://kubernetes.io/docs/getting-started-guides/scratch/#cloud-providers)

For more information, see [#53154](https://github.com/kubernetes/kubernetes/issues/53154).

* `kubectl set` commands placed on ReplicaSet and DaemonSet occasionally return version errors. All set commands, including set image, set env, set resources, and set serviceaccounts, are affected.

For more information, see [#53040](https://github.com/kubernetes/kubernetes/issues/53040).

- If firstTimestamp is not set use eventTime when printing event ([#94252](https://github.com/kubernetes/kubernetes/pull/94252), [@ingvagabund](https://github.com/ingvagabund)) [SIG CLI]

- Fix: set nil cache entry based on old cache ([#87591](https://github.com/kubernetes/kubernetes/pull/87591), [@aramase](https://github.com/aramase)) [SIG Cloud Provider]

  * Authorization sets `authorization.k8s.io/decision` and `authorization.k8s.io/reason` annotations with the authorization decision ("allow" or "forbid") and a human-readable description of why the decision was made (for example, RBAC includes the name of the role/binding/subject which allowed a request).

* Ensured IP is set for Azure internal load balancer. ([#59083](https://github.com/kubernetes/kubernetes/pull/59083), [@feiskyer](https://github.com/feiskyer))

MUST read this before you upgrade)

- Kube-proxy's IPVS proxy mode no longer sets the net.ipv4.conf.all.route_localnet sysctl parameter. Nodes upgrading will have net.ipv4.conf.all.route_localnet set to 1 but new nodes will inherit the system default (usually 0). If you relied on any behavior requiring net.ipv4.conf.all.route_localnet, you must set ensure it is enabled as kube-proxy will no longer set it automatically. This change helps to further mitigate CVE-2020-8558. ([#92938](https...

  - `--service-account-issuer`, should be set to a URL identifying the API server that will be stable over the cluster lifetime.
  - `--service-account-key-file`, set to one or more files containing one or more public keys used to verify tokens.

accidental enablement of the new alpha `optionalOldSelf` API field in CustomResourceDefinition validation rules, which should only be allowed to be set when the CRDValidationRatcheting feature gate is enabled. Existing CustomResourceDefinition objects which have the field set will retain it on update, but new CustomResourceDefinition objects will not be permitted to set the field while the CRDValidationRatcheting feature gate is disabled. ([#122343](https://github.com/kubernetes/kubernetes/pull/122343), [...

ConfigMaps are also allowed) that kubectl can use to accurately and efficiently track set membership across `apply` operations. The format used for `ApplySet` is set out in  [KEP 3659](https://github.com/kubernetes/enhancements/issues/3659) as a low-level specification.  Other tools in the ecosystem can also build on this specification for improved interoperability.  To try the ApplySet-based pruning alpha, set `KUBECTL_APPLYSET=true` and use the flags `--prune --applyset=secret-name` with `kubectl...