- Structured Authentication Configuration now supports configuring multiple JWT authenticators. The maximum allowed JWT authenticators in the authentication configuration is 64. ([#123431](https://github.com/kubernetes/kubernetes/pull/123431), [@aramase](https://github.com/aramase))

* 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))

few seconds. ([#50258](https://github.com/kubernetes/kubernetes/pull/50258), [@liggitt](https://github.com/liggitt))

* 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" by supplying the "google:" username prefix. ([#50875](https://github.com/kubernetes/kubernetes/pull/50875),...

* 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" by supplying the "google:" username prefix. ([#50875](https://github.com/kubernetes/kubernetes/pull/50875),...

* Exec authenticator plugin supports TLS client certificates. ([#61803](https://github.com/kubernetes/kubernetes/pull/61803), [@awly](https://github.com/awly))

- Increased `CSINodeIDMaxLength` from 128 bytes to 192 bytes. ([#98753](https://github.com/kubernetes/kubernetes/pull/98753), [@Jiawei0227](https://github.com/Jiawei0227))
- Kube-apiserver: The OIDC authenticator no longer waits 10 seconds before attempting to fetch the metadata required to verify tokens. ([#97693](https://github.com/kubernetes/kubernetes/pull/97693), [@enj](https://github.com/enj)) [SIG API Machinery and Auth]

- Fix a data race in authentication between AuthenticatedGroupAdder and cached token authenticator. ([#109969](https://github.com/kubernetes/kubernetes/pull/109969), [@sttts](https://github.com/sttts)) [SIG API Machinery and Auth]

- Adds metrics for the delegated authenticator used by extension APIs that delegate authentication logic to the Kube API server. ([#99364](https://github.com/kubernetes/kubernetes/pull/99364), [@p0lyn0mial](https://github.com/p0lyn0mial))