- Overall, enable the feature of `PreferNominatedNode` will  improve the performance of scheduling where preemption might frequently happen, but in theory, enable the feature of `PreferNominatedNode`, the pod might not be scheduled to the best candidate node in the cluster. ([#93179](https://github.com/kubernetes/kubernetes/pull/93179), [@chendave](https://github.com/chendave)) [SIG Scheduling and Testing]

- [`KT-56842`](https://youtrack.jetbrains.com/issue/KT-56842) Light Classes: Primitive-backed context receiver parameters shouldn't be marked with `@NotNull`
- [`KT-56835`](https://youtrack.jetbrains.com/issue/KT-56835) Light classes: Underlying fields for delegated properties should be marked as final and `@NotNull`

* Rescheduler uses taints in v1beta1 and will remove old ones (in version v1alpha1) right after its start. ([#43106](https://github.com/kubernetes/kubernetes/pull/43106), [@piosz](https://github.com/piosz))

### Volumes

For initial installations, see the [Setup topics](https://kubernetes.io/docs/setup/pick-right-solution/) in the Kubernetes documentation.

For more information and for updates on resolution of this issue, see [#51899](https://github.com/kubernetes/kubernetes/issues/51899).

* PodDisruptionBudget now uses [ControllerRef](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/api-machinery/controller-ref.md) to make the right decisions about Pod eviction even if the built in application controllers have overlapping selectors.

### **Security**
#### Admission Control

 - CSINode initialization does not crash kubelet on startup when APIServer is not reachable or kubelet has not the right credentials yet. ([#89589](https://github.com/kubernetes/kubernetes/pull/89589), [@jsafrane](https://github.com/jsafrane)) [SIG Storage]

### Bug or Regression

- Fixes a race condition in the iptables mode of kube-proxy in 1.27 and later
  that could result in some updates getting lost (e.g., when a service gets a
  new endpoint, the rules for the new endpoint might not be added until
  much later). ([#122815](https://github.com/kubernetes/kubernetes/pull/122815), [@wedaly](https://github.com/wedaly)) [SIG Network]

* Pod priority and preemption is now enabled by default. Even if you don't plan to use this feature, you might need to take some action immediately after upgrading. In multi-tenant clusters where not all users are trusted, you are advised to create appropriate quotas for two default priority classes, system-cluster-critical and system-node-critical, which are...

- Kubelet might fail to restart if an existing flexvolume mounted pvc contains a large number of directories, or is full. [#75019](https://github.com/kubernetes/kubernetes/pull/75019)

## Urgent Upgrade Notes