before you upgrade)

- Kube-proxy's IPVS proxy mode no longer sets the net.ipv4.conf.all.route_localnet sysctl parameter. Nodes upgrading will have net.ipv4.conf.all.route_localnet set to 1 but new nodes will inherit the system default (usually 0). If you relied on any behavior requiring net.ipv4.conf.all.route_localnet, you must set ensure it is enabled as kube-proxy will no longer set it automatically. This change helps to further mitigate CVE-2020-8558. ([#92938](https://github.com/k...

### API Change

- '`kube-apiserver`: adds `--authentication-config` flag for reading `AuthenticationConfiguration`
  files. `--authentication-config` flag is mutually exclusive with the existing `--oidc-*`
  flags.' ([#119142](https://github.com/kubernetes/kubernetes/pull/119142), [@aramase](https://github.com/aramase))

    * Implements subPathExpr field for expanding environment variables into a subPath
    * The fields subPathExpr and subPath are mutually exclusive
    * Note: This is a breaking change from the previous version of this alpha feature

- Plugin/PluginConfig and Policy APIs are mutually exclusive when running the scheduler ([#88864](https://github.com/kubernetes/kubernetes/pull/88864), [@alculquicondor](https://github.com/alculquicondor)) [SIG Scheduling]

- Very large patches may now be specified to `kubectl patch` with the `--patch-file` flag instead of including them directly on the command line. The `--patch` and `--patch-file` flags are mutually exclusive. ([#93548](https://github.com/kubernetes/kubernetes/pull/93548), [@smarterclayton](https://github.com/smarterclayton)) [SIG CLI]

* The CRD OpenAPI v3 specification for validation now allows `additionalProperties`, which are mutually exclusive to properties. ([#62333](https://github.com/kubernetes/kubernetes/pull/62333), [@sttts](https://github.com/sttts))

  2. The `--node-cidr-mask-size` flag is mutually exclusive with `--node-cidr-mask-size-ipv4` and `--node-cidr-mask-size-ipv6`.

  Server-side apply now considers `.spec.defaultBackend` to be an atomic struct.  This means that any field-owner who sets values in that struct (they are mutually exclusive) owns the whole struct. For almost all users this change has no impact; for controllers that want to change the default backend port from number to name (or vice-versa), this makes it easier. ([#126207](https://github.com/kubernetes/ku...

- Kube-apiserver: fixes a 1.32+ regression validating OIDC and anonymous authentication flags are mutually exclusive to authentication configuration. Fixes an issue where the kube-apiserver `/flagz` endpoint would not respond correctly with parsed flags value. ([#130332](https://github.com/kubernetes/kubernetes/pull/130332), [@richabanker](https://gi...

* TLS cert storage for self-hosted clusters is now configurable. You can store them as secrets (alpha) or as usual host mounts. ([#50762](https://github.com/kubernetes/kubernetes/pull/50762), [@jamiehannaford](https://github.com/jamiehannaford))