*   Azure NSG rules are now restricted so that external access is allowed only to the load balancer IP. ([#54177](https://github.com/kubernetes/kubernetes/pull/54177),[ @itowlson](https://github.com/itowlson))

<h3 id="Type_unification_rules">Type unification rules</h3>

<p>
The type unification rules describe if and how two types unify.
The precise details are relevant for Go implementations,
affect the specifics of error messages (such as whether
a compiler reports a type inference or other error),
and may explain why type inference fails in unusual code situations.
But by and large these rules can be ignored when writing Go code:

- In "large" clusters, kube-proxy in iptables mode will now sometimes
  leave unused rules in iptables for a while (up to `--iptables-sync-period`)
  before deleting them. This improves performance by not requiring it to
  check for stale rules on every sync. (In smaller clusters, it will still
  remove unused rules immediately once they are no longer used.)

* Ensure the backend pools are set correctly for Azure SLB with multiple backend pools (e.g. outbound rules) ([#76691](https://github.com/kubernetes/kubernetes/pull/76691), [@feiskyer](https://github.com/feiskyer))

- Fixed a bug where kube-proxy returns error due to existing ipset rules using a different hash type. ([#77371](https://github.com/kubernetes/kubernetes/pull/77371), [@andrewsykim](https://github.com/andrewsykim))
- Fixed spurious error messages about failing to clean up iptables rules when using iptables 1.8. ([#77303](https://github.com/kubernetes/kubernetes/pull/77303), [@danwinship](https://github.com/danwinship))

* Ensure the backend pools are set correctly for Azure SLB with multiple backend pools (e.g. outbound rules) ([#76691](https://github.com/kubernetes/kubernetes/pull/76691), [@feiskyer](https://github.com/feiskyer))

- Kube-apiserver: fixes a potential crash serving CustomResourceDefinitions that combine an invalid schema and CEL validation rules. ([#126167](https://github.com/kubernetes/kubernetes/pull/126167), [@cici37](https://github.com/cici37)) [SIG API Machinery and Testing]

- CEL regex patterns in x-kubernetes-valiation rules are compiled when CRDs are created/updated if the pattern is provided as a string constant in the expression. Any regex compile errors are reported as a CRD create/update validation error. ([#108617](https://github.com/kubernetes/kubernetes/pull/108617), [@jpbetz](https://github.com/jpbetz))

### Other notable changes

* Prevent AWS Network Load Balancer security groups ingress rules to be deleted by ensuring target groups are tagged. ([#73594](https://github.com/kubernetes/kubernetes/pull/73594), [@masterzen](https://github.com/masterzen))
* Allow disable outbound SNAT when Azure standard load balancer is used together with outbound rules.  ([#75282](https://github.com/kubernetes/kubernetes/pull/75282), [@feiskyer](https://github.com/feiskyer))

- Use NLB Subnet CIDRs instead of VPC CIDRs in Health Check SG Rules ([#93515](https://github.com/kubernetes/kubernetes/pull/93515), [@t0rr3sp3dr0](https://github.com/t0rr3sp3dr0)) [SIG Cloud Provider]

### Other (Cleanup or Flake)