- Added validation to ensure `log-flush-frequency` is a positive value, returning an error instead of causing a panic. ([#133540](https://github.com/kubernetes/kubernetes/pull/133540), [@BenTheElder](https://github.com/BenTheElder)) [SIG Architecture, Instrumentation, Network and Node]

* fixes a panic applying json patches containing out of bounds operations ([#64355](https://github.com/kubernetes/kubernetes/pull/64355), [@liggitt](https://github.com/liggitt))
* Fix incorrectly propagated ResourceVersion in ListRequests returning 0 items. ([#64150](https://github.com/kubernetes/kubernetes/pull/64150), [@wojtek-t](https://github.com/wojtek-t))

- Fixed recursive LIST from watch cache returning object matching key. ([#125584](https://github.com/kubernetes/kubernetes/pull/125584), [@serathius](https://github.com/serathius)) [SIG API Machinery and Testing]

- PersistentVolumeClaim objects are no longer left with storage class...

  
  **How can I migrate?**
  
  For backward compatibility, nil `QueueingHintFn` is treated as always returning QueueAfterBackoff. 
  So, if you want to just keep the existing behavior, you can register `ClusterEventWithHint` with no `QueueingHintFn` in it. 

- 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]
- Kube-apiserver: fixed a bug returning inconsistent results from list requests which set a field or label selector and set a paging limit ([#94002](https://github.com/kubernetes/kubernetes/pull/94002), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery]

- Added alpha support for `WindowsHostNetworking` feature. ([#112961](https://github.com/kubernetes/kubernetes/pull/112961), [@marosset](https://github.com/marosset))
- Added alpha support for returning container and pod metrics from CRI, instead of cAdvsior. ([#113609](https://github.com/kubernetes/kubernetes/pull/113609), [@haircommander](https://github.com/haircommander))

* Protobuf serialization does not distinguish between `[]` and `null`.
API fields previously capable of storing and returning either `[]` and `null` via JSON API requests (for example, the Endpoints `subsets` field)
can now store only `null` when created using the protobuf content-type or stored in etcd using protobuf serialization (the default in 1.6).

- Kube-apiserver: fixes scale subresource patch handling to avoid returning unnecessary 409 Conflict error to clients ([#90342](https://github.com/kubernetes/kubernetes/pull/90342), [@liggitt](https://github.com/liggitt)) [SIG Apps, Autoscaling and Testing]

- Fix kubelet token cache returning stale tokens when service accounts are recreated with the same name. The token cache is now UID-aware and the new `TokenRequestServiceAccountUIDValidation` feature gate (Beta, enabled by default) validates the TokenRequest UID when set matches the...