- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all entries in the output table is included - for both certificates on disk and in kubeconfig files. ([#106924](https://github.com/kubernetes/kubernetes/pull/106924), [@neolit123](https://gi...

### Signing Release Artifacts

Release artifacts are [signed](https://github.com/kubernetes/enhancements/issues/3031) using [cosign](https://github.com/sigstore/cosign)
signatures
and there is experimental support for [verifying image signatures](https://kubernetes.io/docs/tasks/administer-cluster/verify-signed-images/).

- Added secure port 10259 to the kube-scheduler (enabled by default) and deprecate old insecure port 10251. Without further flags self-signed certs are created on startup in memory. ([#69663](https://github.com/kubernetes/kubernetes/pull/69663), [@sttts](https://github.com/sttts))

## Release Notes From SIGs

### SIG API Machinery

- Addressed an issue where a JWT authenticator set up via `--authentication-config` would encounter failures in verifying tokens not signed with RS256. ([#123282](https://github.com/kubernetes/kubernetes/pull/123282), [@enj](https://github.com/enj))

  - The requested name did not match the set of authorized names (`x509.HostnameError`)
  - The error surfaced after attempting a connection contained one of the substrings: "certificate is not trusted" or "certificate signed by unknown authority". ([#120736](https://github.com/kubernetes/kubernetes/pull/120736), [@MadhavJivrajani](https://github.com/MadhavJivrajani))

* 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))

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all entries in the output table is included - for both certificates on disk and in kubeconfig files. ([#106925](https://github.com/kubernetes/kubernetes/pull/106925), [@neolit123](https://gi...

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all entries in the output table is included - for both certificates on disk and in kubeconfig files. ([#106923](https://github.com/kubernetes/kubernetes/pull/106923), [@neolit123](https://gi...

- Kubeadm: during 'upgrade apply', if the kube-proxy ConfigMap is missing, assume that kube-proxy...

  - The requested name does not match the set of authorized names (x509.HostnameError)
  - The error surfaced after attempting a connection contains one of the substrings: "certificate is not trusted" or "certificate signed by unknown authority" ([#120767](https://github.com/kubernetes/kubernetes/pull/120767), [@MadhavJivrajani](https://github.com/MadhavJivrajani)) [SIG Architecture and Cloud Provider]