- Kubelet: close a loophole where static pods could reference arbitrary ResourceClaims. The pods created by the kubelet then don't run due to a sanity check, but such references shouldn't be allowed regardless. ([#131875](https://github.com/kubernetes/kubernetes/pull/131875), [@pohly](https://github.com/pohly)) [SIG Apps, Auth and Node]

  
  When adding links which point to resources within git repositories, like
  KEPs or supporting documentation, please reference a specific commit and avoid
  linking directly to the master branch. This ensures that links reference a
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* kubelet: resolved hang/timeout issues when running large numbers of pods with unique configmap/secret references ([#74755](https://github.com/kubernetes/kubernetes/pull/74755), [@liggitt](https://github.com/liggitt))

existing functions, and on making security functions more understandable for users.

RBAC [cluster role aggregation](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#aggregated-clusterroles), introduced in 1.9, graduated to stable status with no changes in 1.11, and [client-go credential plugins](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#client-go-credential-plugins)  graduated to beta status, while also adding support for obtaining TLS credentials from...

- Kubelet: close a loophole where static pods could reference arbitrary ResourceClaims. The pods created by the kubelet then don't run due to a sanity check, but such references shouldn't be allowed regardless. ([#131876](https://github.com/kubernetes/kubernetes/pull/131876), [@pohly](https://github.com/pohly)) [SIG Apps, Auth and Node]

    * Action required: change references to feature gate RequestManagement into references to APIPriorityAndFairness

- client-go releases will no longer have bootstrap (k8s.io/client-go/tools/bootstrap) related code. Any reference to it will break. Please redirect all references to k8s.io/bootstrap instead. ([#67356](https://github.com/kubernetes/kubernetes/pull/67356), [@yliaog](https://github.com/yliaog))

* CustomResourceDefinitions: OpenAPI v3 validation schemas containing `$ref`references are no longer permitted (valid references could not be constructed previously because property ids were not permitted either). Before upgrading, ensure CRD definitions do not include those `$ref` fields. ([#58438](https://github.com/kubernetes/kubernetes/pull/58438),...

- Duplicate owner reference entries in create/update/patch requests now get deduplicated by the API server. The client sending the request now receives a warning header in the API response. Clients should stop sending requests with duplicate owner references. The API server may reject such requests as early as 1.24. ([#96185](https://github.com/kubernetes/kubernetes/pull/96185), [@royc...

- Kubelet: Closed a loophole that allowed static Pods to reference arbitrary ResourceClaims. Even though these Pods failed to run due to a sanity check, such references are now explicitly disallowed. ([#131844](https://github.com/kubernetes/kubernetes/pull/131844), [@pohly](https://github.com/pohly)) [SIG Apps, Auth and Node]