- Kube-apiserver: regular expressions specified with the `--cors-allowed-origins` option are now validated to match the entire `hostname` inside the `Origin` header of the request and 
  must contain '^' or the '//' prefix to anchor to the start, and '$' or the port separator ':' to anchor to 

- Upgrades `IPv6Dualstack` to `Beta` and turns it on by default. New clusters or existing clusters are not be affected until an actor starts adding secondary Pods and service CIDRS CLI flags as described here: [IPv4/IPv6 Dual-stack](https://github.com/kubernetes/enhancements/tree/master/keps/sig-network/563-dual-stack) ([#98969](https://github.com/kubernetes/kubernetes/pull/98969),...

#### kubernetes Core Known Issues

- Kube Proxy crashes infrequently due to a docker bug ([#24000](https://github.com/docker/docker/issues/24000))
  - This issue can be resolved by restarting docker daemon
- CORS works only in insecure mode ([#24086](https://github.com/kubernetes/kubernetes/issues/24086))

* Fixes in HPA: consider only running pods; proper denominator in avg request calculations. ([#33735](https://github.com/kubernetes/kubernetes/pull/33735), [@jszczepkowski](https://github.com/jszczepkowski))