- Users might specify the `kubectl.kubernetes.io/default-exec-container` annotation in a Pod to preselect container for kubectl commands. ([#97099](https://github.com/kubernetes/kubernetes/pull/97099), [@pacoxu](https://github.com/pacoxu)) [SIG CLI]

### Feature

- Kubelet metrics have been changed to buckets. For example the `exec/{podNamespace}/{podID}/{containerName}` is now just exec. ([#87913](https://github.com/kubernetes/kubernetes/pull/87913), [@cheftako](https://github.com/cheftako)) [SIG Node]

* CRI: Add stdout/stderr fields to Exec and Attach requests. ([#52686](https://github.com/kubernetes/kubernetes/pull/52686), [@yujuhong](https://github.com/yujuhong))
* Cluster Autoscaler 1.0.0 ([#53005](https://github.com/kubernetes/kubernetes/pull/53005), [@mwielgus](https://github.com/mwielgus))

kubernetes/kubernetes/pull/58973), [@verb](https://github.com/verb))

* The default Flexvolume plugin directory for COS images on GCE has changed to `/home/kubernetes/flexvolume`, rather than `/etc/srv/kubernetes/kubelet-plugins/volume/exec`. Existing Flexvolume installations in clusters using COS images must be moved to the new directory, and installation processes must be updated with the new path. ([#58171](https://github.com/kubernetes/kubernetes/pull/58171), [@verult](https://github.com/verult))...

- Changed the error message to `cannot exec into multiple objects at a time` when file passed to `kubectl exec` contains multiple resources ([#114249](https://github.com/kubernetes/kubernetes/pull/114249), [@ardaguclu](https://github.com/ardaguclu))

- `kubectl run` can set a service account name in the generated pod
  spec with the `--serviceaccount` flag.

- `kubectl proxy` now correctly handles the `exec`, `attach`, and
  `portforward` commands.  You must pass `--disable-filter` to the command to allow these commands.

- Added `cronjobs.batch` to "all", so that `kubectl get all` returns them.

## Urgent Upgrade Notes 

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

### Bug or Regression

- Fix an ephemeral port exhaustion bug caused by improper connection management that occurred when a large number of objects were handled by kubectl while exec auth was in use. ([#112337](https://github.com/kubernetes/kubernetes/pull/112337), [@enj](https://github.com/enj)) [SIG API Machinery and Auth]

This release also contains a number of bug fixes to the feature set. Aspiring plugin authors can look at [sample-exec-plugin](https://github.com/ankeesler/sample-exec-plugin) as a way to get started.

- Kubelet metrics have been changed to buckets. 
  For example the exec/{podNamespace}/{podID}/{containerName} is now just exec. ([#87913](https://github.com/kubernetes/kubernetes/pull/87913), [@cheftako](https://github.com/cheftako)) [SIG Node]