**[Pod priority and preemption](https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/) is now enabled by default.** Note that this means that pods from *any* namespace can now request priority classes that compete with and/or cause preemption of critical system pods that are already running. If that is not desired, disable the PodPriority feature by setting `--feature-gates=PodPriority=false` on the kube-apiserver, kube-scheduler, and kubelet components before upgrading to 1.11....

external etcd endpoints passed in the `ClusterConfiguration` that have Unicode characters are no longer IDNA encoded (converted to Punycode). They are now just URL encoded as per Go's implementation of RFC-3986, have duplicate "/" removed from the URL paths, and passed like that directly to the `kube-apiserver` `--etcd-servers` flag. If you have etcd endpoints that have Unicode characters, it is advisable to encode them in advance with tooling that is fully IDNA compliant. If you don't do that, the Go standard...

    - [<code>CSIMigrationvSphere</code> feature gate has not migrated to new CRD APIs](#csimigrationvsphere-feature-gate-has-not-migrated-to-new-crd-apis)
    - [Workloads that saturate nodes with pods may see pods that fail due to node admission](#workloads-that-saturate-nodes-with-pods-may-see-pods-that-fail-due-to-node-admission)
    - [Etcd v3.5.[0-2] data corruption](#etcd-v350-2-data-corruption)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)

This release contains changes that address the following vulnerabilities:

### CVE-2021-25735: Validating Admission Webhook does not observe some previous fields

A security issue was discovered in kube-apiserver that could allow node
updates to bypass a Validating Admission Webhook. You are only affected
by this vulnerability if you run a Validating Admission Webhook for Nodes

SIG Node focused on stability and performance improvements in the 1.13 release.  A new alpha feature is introduced to improve the mechanism that nodes heartbeat back to the control plane.  The `NodeLease` feature results in the node using a `Lease` resource in the `kube-node-lease` namespace that is renewed periodically.  The `NodeStatus` that was used previously to heartbeat back to the control plane is only updated when it changes.  This reduces load on the control plane for large clusters....

- Added a test to guarantee that conformance clusters require at least 2 untainted nodes. ([#106313](https://github.com/kubernetes/kubernetes/pull/106313), [@aojea](ht...

- Verify that CRD default values in OpenAPI specs are pruned, with the exceptions of values under `metadata`. ([#78829](https://github.com/kubernetes/kubernetes/pull/78829), [@sttts](https://github.com/sttts))
- Fixes a bug that when there is a "connection refused" error, the reflector's ListAndWatch func will return directly but what expected is that sleep 1 second and rewatch since the specified resourceVersion.

### Promoted core CSI Migration to Stable

  // The scheduler will prefer to schedule pods to nodes that satisfy
  // the affinity expressions specified by this field, but it may choose
  // a node that violates one or more of the expressions. The node that is
  // most preferred is the one with the greatest sum of weights, i.e.
  // for each node that meets all of the scheduling requirements (resource

- [`KT-57429`](https://youtrack.jetbrains.com/issue/KT-57429) K2: Fix computing a mangled name for members of a generic class that reference the class's type parameters in their signature
- [`KT-57566`](https://youtrack.jetbrains.com/issue/KT-57566) K2: Fix name mangling for functions that have dynamic type in their signature