Container Engine for Kubernetes continues to support Kubernetes version 1.18.10, and Oracle continues to recommend you upgrade your Kubernetes environment to version 1.18.10.

Kubernetes patch versions 1.17.13, 1.16.15, and 1.15.12 have been released to address security vulnerabilities in earlier Kubernetes versions as follows.

• Kubernetes patch version 1.17.13 addresses CVE-2020-8564 , CVE-2020-8566, and CVE-2020-16845 found in earlier 1.17.x releases.
• Kubernetes patch version 1.16.15 addresses CVE-2020-8555, CVE-2020-8557, CVE-2020-8558, CVE-2020-8559, and CVE-2020-16845 found in earlier 1.16.x releases.
• Kubernetes patch version 1.15.12 addresses CVE-2020-8555 found in earlier 1.15.x releases.

Container Engine for Kubernetes now supports Kubernetes patch versions 1.17.13, 1.16.15, and 1.15.12.

Note the following:

• You can upgrade master nodes through unsupported minor versions. Kubernetes requires that you upgrade master nodes one minor version at a time. So if a master node is running Kubernetes version 1.13.5 (an unsupported minor version), upgrade it to Kubernetes version 1.14.8 (also an unsupported minor version), before upgrading it to 1.15.12.
• A number of Kubernetes API versions and Kubernetes labels are deprecated in Kubernetes version 1.16. Before upgrading to Kubernetes version 1.16, you must update any manifest files referring to the deprecated API versions and labels. For more information about the deprecations and what you need to do, see Notes about Container Engine for Kubernetes Support for Kubernetes Version 1.16.

• Container Engine for Kubernetes ceased support for Kubernetes version 1.14.8 on 15 December, 2020. As a result, you are no longer be able to:

  • create new clusters running Kubernetes version 1.14.8
  • add new node pools to existing clusters running Kubernetes version 1.14.8

  If you currently have existing clusters running Kubernetes version 1.14.8, Oracle strongly recommends you immediately upgrade those clusters to Kubernetes version 1.15.12, version 1.16.15, version 1.17.13, or version 1.18.10.

• Container Engine for Kubernetes will cease support for Kubernetes version 1.15.12 on 2 February, 2021. As a result, you will no longer be able to:

  • create new clusters running Kubernetes version 1.15.12
  • add new node pools to existing clusters running Kubernetes version 1.15.12

  If you currently have existing clusters running Kubernetes version 1.15.12, Oracle strongly recommends you immediately upgrade those clusters to Kubernetes version 1.16.15, version 1.17.13, or version 1.18.10.

To upgrade a cluster to a new Kubernetes minor version:

1. Upgrade the Kubernetes version running on the master nodes by following the instructions here. 
2. Having upgraded the master nodes in the cluster, upgrade the Kubernetes version running on worker nodes in a node pool by following the instructions here.

When upgrading master nodes and worker nodes, always follow the Kubernetes skew policy for Kubernetes minor version support. For example, if the master nodes in a cluster are running Kubernetes version 1.18.10, then the worker nodes must be running 1.18.10, 1.17.13, or 1.16.15. Note that although the worker nodes in a node pool must follow the Kubernetes skew policy, you do not have to upgrade them one minor version at a time.

For more information, see Upgrading Clusters to Newer Kubernetes Versions.