- Fixed a bug that caused apiservers to send an inappropriate Content-Type request header to authorization, token authentication, imagepolicy admission, and audit webhooks when the alpha client-go feature gate "ClientsPreferCBOR" is enabled. ([#132960](https://github.com/kubernetes/kubernetes/pull/132960), [@benluddy](https://github.com/benluddy)) [SIG API Machinery and Node]

- Kube-apiserver: timeouts configured for authorization webhooks in the --authorization-config file are now honored, and webhook timeouts are accurately reflected in webhook metrics with result=timeout ([#125552](https://github.com/kubernetes/kubernetes/pull/125552), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth and Testing]

    /** Property key for Slack webhook URLs configuration. */
    public static final String SLACK_WEBHOOK_URLS_PROPERTY = "slack.webhook.urls";

    /** Property key for Google Chat webhook URLs configuration. */
    public static final String GOOGLE_CHAT_WEBHOOK_URLS_PROPERTY = "google.chat.webhook.urls";

    /** Property key for browser locale usage in search configuration. */

- Changed apiserver to treat failures decoding a mutating webhook patch as failures to call the webhook so they trigger the webhook failurePolicy and count against metrics like `webhook_fail_open_count` ([#131627](https://github.com/kubernetes/kubernetes/pull/131627), [@dims](https://github.com/dims)) [SIG API Machinery]

- kube-apiserver: Promoted `AuthorizeWithSelectors` feature to beta, which includes field and label selector information from requests in webhook authorization calls. Promoted `AuthorizeNodeWithSelectors` feature to beta, which changes node authorizer behavior to limit requests from node API clients, so that each Node can only get / list / watch its own Node API object, and can also only get...