* Fix metrics API group name in audit configuration ([#53493](https://github.com/kubernetes/kubernetes/pull/53493), [@piosz](https://github.com/piosz))
* Use separate client for leader election in scheduler to avoid starving leader election by regular scheduler operations. ([#53793](https://github.com/kubernetes/kubernetes/pull/53793), [@wojtek-t](https://github.com/wojtek-t))

- Added a path `/header?key=` to `agnhost netexec` allowing one to view what the header value is of the incoming request.

  Ex:
  ```
  $ curl -H "X-Forwarded-For: something" 172.17.0.2:8080/header?key=X-Forwarded-For
  something
  ```

- Leader Migration for controller managers graduated to beta. ([#103533](https://github.com/kubernetes/kubernetes/pull/103533), [@jiahuif](https://github.com/jiahuif)) [SIG API Machinery and Cloud Provider]

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.

    - [CVE-2023-3955: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3955-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
    - [CVE-2023-3676: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3676-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
  - [Changes by Kind](#changes-by-kind-11)

- kube-apiserver: a new `--requestheader-uid-headers` flag allows configuring request header authentication to obtain the authenticating user's UID from the specified headers. The suggested value for the new option is `X-Remote-Uid`. When specified, the `kube-system/extension-apiserver-authentication` configmap will include the value in its `.data[requestheader-uid-headers]` field. ([#115834](https://github.com/kubernetes/kubernetes/pull/115834), [@stlaz](...

- Added Coordinated Leader Election as Alpha under the `CoordinatedLeaderElection` feature gate. With the feature enabled, the control plane can use LeaseCandidate objects (coordination.k8s.io/v1alpha1 API group) to participate in a leader election and let the kube-apiserver select the best instance according to some strategy. ([#124012](https://github.com/kubernetes/kubernetes/pull/124012),...

    - [CVE-2023-3955: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3955-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
    - [CVE-2023-3676: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3676-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
  - [Changes by Kind](#changes-by-kind-14)

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. The Kubelet plugin...

- Added ControllerManagerReleaseLeaderElectionLockOnCancel feature gate to gate leader election lock release on exit for kube-controller-manager ([#136279](https://github.com/kubernetes/kubernetes/pull/136279), [@tchap](https://github.com/tchap)) [SIG API Machinery and Cloud Provider]