- A namespaced object with an ownerReference referencing a uid of a namespaced kind which does not exist in the same namespace is now consistently treated as though that owner does not exist, and the child object is deleted.

### Bug or Regression

- Fixes a spurious "namespace not found" error possible in default configurations in 1.30+ when using ValidatingAdmissionPolicy or MutatingAdmissionPolicy to intercept namespaced objects in newly-created namespaces ([#135444](https://github.com/kubernetes/kubernetes/pull/135444), [@lalitc375](https://github.com/lalitc375)) [SIG API Machinery]

    ([kubernetes/features#70](https://github.com/kubernetes/enhancements/issues/70))
  - [alpha] Creating a `Federated Namespace` causes matching
    `Namespace`s to be created and maintained in all the clusters registered with that federation. ([docs](http://kubernetes.io/docs/user-guide/federation/federated-namespaces.md)) ([kubernetes/features#69](https://github.com/kubernetes/enhancements/issues/69))

- Fixed a spurious `namespace not found` error in default `v1.30+` configurations when using `ValidatingAdmissionPolicy` or `MutatingAdmissionPolicy` to intercept namespaced objects in newly-created namespaces. ([#135359](https://github.com/kubernetes/kubernetes/pull/135359), [@liggitt](https://github.com/liggitt))

### SIG Service Catalog

The Service Plan Defaults feature is still under active development.
We continue to improve the UX for the svcat CLI, specifically filling in gaps for the new Namespaced Service Broker feature.

### SIG Storage

- Fixes a spurious "namespace not found" error possible in default configurations in 1.30+ when using ValidatingAdmissionPolicy or MutatingAdmissionPolicy to intercept namespaced objects in newly-created namespaces ([#135443](https://github.com/kubernetes/kubernetes/pull/135443), [@lalitc375](https://github.com/lalitc375)) [SIG API Machinery]

#### ThirdPartyResource

If you use ThirdPartyResource objects, they have moved from being namespaced-scoped to be cluster-scoped. Before upgrading to 1.3.0, export and delete any existing ThirdPartyResource objects using a 1.2.x client:

kubectl get thirdpartyresource --all-namespaces -o yaml > tprs.yaml
kubectl delete -f tprs.yaml

  For more information, see [#47131](https://github.com/kubernetes/kubernetes/issues/47131)

*   If a namespaced resource is owned by a cluster scoped resource, and the namespaced dependent is processed before the cluster scoped owner has ever been observed by the garbage collector, the dependent will be erroneously deleted.

- Critical pods can now be created in namespaces other than kube-system. To limit critical pods to the kube-system namespace, cluster admins should create an admission configuration file limiting critical pods by default, and a matching quota object in the `kube-system` namespace permitting critical pods in that namespace. See https://kubernetes.io/docs/concepts/policy/resource-quotas/#limit-priority-class-consumption-by-default...

### API Change

- 1. PodAffinityTerm includes a namespaceSelector field to allow selecting eligible namespaces based on their labels.