- A `create` or `update` API request with duplicate items in a keyed list no longer wipes out managedFields. Examples include env var entries with the same name, or port entries with the same containerPort in a pod spec.

- CustomResourceDefinition schemas that use `x-kubernetes-list-map-keys` to specify properties that uniquely identify list items must make those properties required or have a default value, to ensure those properties are present for all list items. See https://kubernetes.io/docs/reference/using-api/api-concepts/#merge-strategy for details. ([#88076](https://github.com/kubernetes/kubernetes/pull/88076), [@eloyekunle](https://github.com/eloyekunle))...

- CRDs can have fields named `type` with value `array` and nested array with `items` fields without validation to fall over this. ([#85223](https://github.com/kubernetes/kubernetes/pull/85223), [@sttts](https://github.com/sttts))

### Apps

- Fixes a bug where `MutatingAdmissionPolicy` would fail to apply to objects with duplicate list items (like env vars). ([#135560](https://github.com/kubernetes/kubernetes/pull/135560), [@lalitc375](https://github.com/lalitc375) [SIG API Machinery]

- The Kubernetes API server now correctly detects and closes existing TLS connections when its client...

- Bookmark events are now sent immediately after all items in the watchCache store have been processed, improving consistency in client behavior. ([#127012](https://github.com/kubernetes/kubernetes/pull/127012), [@Chaunceyctx](https://github.com/Chaunceyctx))