July 31, 2025 - CKS Kubernetes upgrade support

CKS now supports Kubernetes upgrades with updated control group defaults

Update CKS CKS now supports Kubernetes upgrades with updated control group defaults.

Version sequence

• Clusters can only be upgraded to the next Kubernetes minor version (for example, from 1.32 to 1.33).
• All upgrades must be sequential - if newer versions exist, you must upgrade one version at a time. You cannot skip versions.
• Downgrades are not supported once an upgrade has been performed.

Eligibility

A cluster is not eligible for an upgrade if:

• The configuration is not supported: Some clusters do not support self-service upgrades when internal components are out of date or not enabled.
• The cluster uses deprecated Kubernetes APIs: If a cluster uses Kubernetes APIs that are deprecated in the target version, the upgrade cannot proceed.

Note

CoreWeave checks for deprecated APIs in your cluster, but cannot guarantee that all deprecated APIs in use are detected. Before upgrading, review the Kubernetes release notes for your target version and ensure that your workloads are compatible.

• The cluster is not healthy: Upgrades require the cluster to be in a healthy state.
• The Nodes are out of date: If any Nodes are more than two versions behind the Control Plane, the upgrade cannot proceed until those Nodes are rebooted, causing them to upgrade to the latest kubelet version.

Upgrade process

For detailed instructions on upgrading your cluster, see Upgrade Kubernetes.