this validation could allow authenticated requests destined for Nodes to be redirected to the API Server through its private network.

The merged fix enforces validation against the proxying address for a Node. In some cases, the fix can break clients that depend on the `nodes/proxy` subresource, specifically if a kubelet advertises a localhost or link-local address to the Kubernetes control plane. Configuring an egress proxy for egress to the cluster network can also mitigate this vulnerability....