- kube-apiserver: setting a `dryRun` query parameter on a CONNECT request will now cause the request to be rejected, consistent with behavior of other mutating API requests. Examples of CONNECT APIs are the `nodes/proxy`, `services/proxy`, `pods/proxy`, `pods/exec`, and `pods/attach` subresources. Note that this prevents sending a `dryRun` parameter to backends via `{nodes,...

* API server authentication now caches successful bearer token authentication results for a few seconds. ([#50258](https://github.com/kubernetes/kubernetes/pull/50258), [@liggitt](https://github.com/liggitt))

- Fixed a bug where `kubectl port-forward`, when used with a Deployment, could connect to a terminating pod even when a running pod is also available. ([#119256](https://github.com/kubernetes/kubernetes/pull/119256), [@brianpursley](https://github.com/brianpursley)) [SIG CLI]

* kube-apiserver: the OpenID Connect authenticator can now verify ID Tokens signed with JOSE algorithms other than RS256 through the --oidc-signing-algs flag. ([#58544](https://github.com/kubernetes/kubernetes/pull/58544), [@ericchiang](https://github.com/ericchiang))

* The OpenID Connect authenticator can now use a custom prefix, or omit the default prefix, for username and groups claims through the --oidc-username-prefix and --oidc-groups-prefix flags. For example, the authenticator can map a user with the username "jane" to "google:jane"...

- Turn CronJobControllerV2 on by default. ([#98878](https://github.com/kubernetes/kubernetes/pull/98878), [@soltysh](https://github.com/soltysh)) [SIG Apps]
- UDP protocol support for Agnhost connect subcommand ([#98639](https://github.com/kubernetes/kubernetes/pull/98639), [@knabben](https://github.com/knabben)) [SIG Testing]

    * A distributed claim allows the OIDC provider to delegate a claim to a
    * separate URL.  Distributed claims are of the form as seen below, and are
    * defined in the OIDC Connect Core 1.0, section 5.6.2.
    * For details, see:
    * http://openid.net/specs/openid-connect-core-1_0.html#AggregatedDistributedClaims

### Auth

- Fixed OpenID Connect (OIDC) token refresh when the client secret contains a special character. ([#76914](https://github.com/kubernetes/kubernetes/pull/76914), [@tsuna](https://github.com/tsuna))

- Kubeadm: used `ttlSecondsAfterFinished` to automatically clean up the `upgrade-health-check`...

* Support whitespace in command path for gcp auth plugin ([#41653](https://github.com/kubernetes/kubernetes/pull/41653), [@jlowdermilk](https://github.com/jlowdermilk))
* client-go no longer imports GCP OAuth2 and OpenID Connect packages by default. ([#41532](https://github.com/kubernetes/kubernetes/pull/41532), [@ericchiang](https://github.com/ericchiang))