- Fixed a bug in ValidatingAdmissionPolicy that caused policies which were using CRD parameters to fail to synchronize ([#123080](https://github.com/kubernetes/kubernetes/pull/123080), [@alexzielenski](https://github.com/alexzielenski)) [SIG API Machinery and Testing]

* Fix a bug in CRD openapi controller that user-defined CRD can overwrite OpenAPI definition/path for the CRD API. ([#81436](https://github.com/kubernetes/kubernetes/pull/81436), [@roycaihw](https://github.com/roycaihw))

- Fixed bug where providing a FieldPath to a CRD Validation Rule would erroneously affect the reported field path of other unrelated CRD Validation Rules on the same schema. ([#123475](https://github.com/kubernetes/kubernetes/pull/123475), [@alexzielenski](https://github.com/alexzielenski))

## Changelog since v1.27.5

## Changes by Kind

### API Change

- Fixed a bug where CEL expressions in CRD validation rules would incorrectly compute a high estimated cost for functions that return strings, lists or maps.

### Bug or Regression

- Fix nil pointer panic in BuildOpenAPIV2 and BuildOpenAPIV3 utilities, used by kube-apiserver's openAPI controller, when a CRD is missing version the requested version. ([#128940](https://github.com/kubernetes/kubernetes/pull/128940), [@jpbetz](https://github.com/jpbetz)) [SIG API Machinery]

* Add generate-groups.sh and generate-internal-groups.sh to k8s.io/code-generator to easily run generators against CRD or User API Server types. ([#52186](https://github.com/kubernetes/kubernetes/pull/52186), [@sttts](https://github.com/sttts))

- Fixed a bug in ValidatingAdmissionPolicy that caused policies which were using CRD parameters to fail to synchronize ([#123003](https://github.com/kubernetes/kubernetes/pull/123003), [@alexzielenski](https://github.com/alexzielenski)) [SIG API Machinery and Testing]

### Promoted CRD Validation Expression Language to Beta

council.aero
country
coupon
coupons
courses
coz.br
cpa
cpa.pro
cprapid.com
cpserver.com
cq.cn
cr
cr.it
cr.ua
craft.me
cranky.jp
crap.jp
crd.co
credit
creditcard
creditunion
cremona.it
crew.aero
cri.br
cri.nz
cricket
crimea.ua
crotone.it
crown
crs
cruise
cruises
cs.in
cs.it

- To enhance usability and developer experience, CRD validation rules now support direct use of (CEL) reserved keywords as field names in object validation expressions.