RHSA-2026:48670 - Security Advisory

Topic

Red Hat OpenShift Container Platform release 4.21.27 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 Critical. 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 4.21.27. See the following advisory for the RPM packages for this release:

https://access.redhat.com/errata/RHBA-2026:48668

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:aaeee8b27a23a8a8923ca2f37dfeabac3c716b4fbecb249f91d0b377323c87b1

(For s390x architecture)
The image digest is sha256:9ba1339f035fc9331e5165e37bce45525c7e30b4e1fa20492468a001e108970f

(For ppc64le architecture)
The image digest is sha256:0488e8a0d59828d11f3447174dcbe68b81a76d1d1e30dcd0640222b0759fd57d

(For aarch64 architecture)
The image digest is sha256:7e9da63ad9c292e8f3d586e9c07d59f895ca80e3d42df83ebd5397e52f075fca

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

• BZ - 2461607
• BZ - 2461626
• BZ - 2461630
• BZ - 2500695
• BZ - 2502690
• OCPBUGS-76552 - Azure: Failed to create cluster with UserManaged Boot Diagnostics
• OCPBUGS-84306 - The Openstack platform should create a TCP Amphora LoadBalancer when LoadBalancerService ingressController is created on Openshift
• OCPBUGS-97922 - False positive ClusterNetworkCIDRConflict on KubeVirt NodePools due to OVN-Kubernetes overlay IP detection
• OCPBUGS-98987 - [4.21] Automatically logged out of the OpenShift web console too frequently
• OCPBUGS-99015 - [release-4.21]: Missing RELATED_IMAGE for runtime-extractor on HyperShift
• OCPBUGS-99276 - [4.21] Zombie logical switch port for deleted virtualmachineinstance on localnet secondary network causes connectivity issues
• OCPBUGS-99277 - [4.21] Virtual machine startup is stuck with error: "Failed to discover live migration status: unexpected live migration state at pods"
• OCPBUGS-99307 - 4.21 agent-installer OVE installation fails due to custom-manifests
• OCPBUGS-99400 - [release-4.21] - Kube-state metrics pod is in Error state as failing to parse the cron job schedule
• OCPBUGS-99446 - Alertmanager crashes when the configuration includes mute/active intervals with a timezone location
• OCPBUGS-99477 - openshift/ovn-kubernetes 5 unit tests failing in SecondaryNodeNetworkController
• OCPBUGS-99544 - [release-4.21] - '0 B' is shown on details page when create pvc with 'EiB' unit.
• OCPBUGS-99546 - [release-4.21] - Incorrect translations for 'CatalogSources' and 'OperatorGroups' in locales/{xx}/olm.json
• OCPBUGS-99641 - EgressIP pod-to-pod connectivity fails across different clusterNetwork CIDRs due to missing cross-subnet no-reroute policies
• OCPBUGS-99646 - HCP AWS | cloud API bypass fails when management cluster requires a proxy
• OCPBUGS-99647 - Update agent-installer-utils to use agent-preinstall-image-builder from quay-proxy
• OCPBUGS-99671 - Backport node_e2e test migrations from main to release-4.21
• OCPBUGS-99763 - [release-4.21] CMO: fallback to kube-system/global-pull-secret for telemeter-client token
• OCPBUGS-99781 - /etc/localtime /usr/share/zoneinfo vanished from ART base images in 4.20.29 4.21.24 4.22.0
• OCPBUGS-99907 - Update OVE UI Konflux references

CVEs

• CVE-2026-16242
• CVE-2026-42033
• CVE-2026-42039
• CVE-2026-42043
• CVE-2026-49978

References

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