RHSA-2026:25187 - Security Advisory

Topic

Red Hat OpenShift Container Platform release 4.21.20 is now available with updates to packages and images that fix several bugs and add enhancements.

This release includes a security update for Red Hat OpenShift Container Platform 4.21.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or private cloud deployments.

This advisory contains the container images for Red Hat OpenShift Container Platform 4.21.20. See the following advisory for the RPM packages for this release:

https://access.redhat.com/errata/RHBA-2026:25185

Space precludes documenting all of the container images in this advisory. See the following Release Notes documentation, which will be updated shortly for this release, for details about these changes:

https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/release_notes/

Solution

For OpenShift Container Platform 4.21 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update:

https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/release_notes/

You may download the oc tool and use it to inspect release image metadata for x86_64, s390x, ppc64le, and aarch64 architectures. The image digests may be found at https://quay.io/repository/openshift-release-dev/ocp-release?tab=tags.

The sha values for the release are as follows:

(For x86_64 architecture)
The image digest is sha256:e2f30027fa1240272c8a472d6c77218ebc486bb966b6862c121187801a40163b

(For s390x architecture)
The image digest is sha256:84aafe31c3f70600df9b6466f6d1f758701c46ef306105af008964478a8e1431

(For ppc64le architecture)
The image digest is sha256:4ec235e09584bc41d185f7e16405d978ec943670de859260fde0ba150fc12fb0

(For aarch64 architecture)
The image digest is sha256:37b527aab81b3151268ea260005b088a7814bfbf55dd0e00cc1c23993bb14eaa

All OpenShift Container Platform 4.21 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html-single/updating_clusters/index#updating-cluster-cli.

Affected Products

• Red Hat OpenShift Container Platform

Fixes

• OCPBUGS-86842 - [4.21] openshift-catalogd filling up ephemeral disk when unable to unpack the clustercatalogs
• OCPBUGS-86979 - [Automated] Update AMI Whitelist
• OCPBUGS-86991 - Flaky TestPrometheusMetrics/openshift-state-metrics test in CMO end-to-end tests
• OCPBUGS-87002 - Router pods restart upon hitting maxconn
• OCPBUGS-87008 - OCL test suite has some flakes
• OCPBUGS-87159 - [release-4.21] Control plane status icon remains grey after upgrading OpenShift cluster to version 4.20.23
• OCPBUGS-87191 - [release-4.21] Manage runtime extractor deployment directly in IO
• BZ - 2449833
• BZ - 2455470
• BZ - 2457729
• OCPBUGS-84370 - [release-4.21] Ironic unneccesarily attempts to boot ramdisk for service steps that results in a maintenance hardware driven reboot
• OCPBUGS-85149 - Fix e2e tests to work on platforms with unmanaged DNS
• OCPBUGS-85478 - Force rebuild machine-os-images for OCP 4.21
• OCPBUGS-85674 - 4.21 - Web Console Corrupts Binary Secret Data (JAR/JCEKS) When Editing Other Fields
• OCPBUGS-86003 - The net namespace was deleted, but its associated file remains in the `/var/run/netns` directory, preventing a POD from starting
• OCPBUGS-86576 - MCPs should degrade or otherwise present an error when a package install is not successful
• OCPBUGS-86581 - [release-4.21] - Terminal - opt key acts as "meta" key in macOS
• OCPBUGS-86805 - [release-4.21]: Add runtime extractor disable option to insights-config ConfigMap

CVEs

• CVE-2026-33186
• CVE-2026-34986
• CVE-2026-35469

References

• https://access.redhat.com/security/updates/classification/