ESB-2026.3761 — Vulnetix

ESB-2026.3761 PUBLISHED CVSS 8.100000381469727 HIGH

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.3761 OpenShift Container Platform 4.21.10 bug fix and security update 16 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: OpenShift Container Platform 4.21.10 Publisher: Red Hat Operating System: Red Hat Resolution: Patch/Upgrade CVE Names: CVE-2026-33186 Original Bulletin: https://access.redhat.com/errata/RHSA-2026:7245 Comment: CVSS (Max): 8.1 CVE-2026-33186 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N) CVSS Source: Red Hat Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N EPSS (Max): 0.0% (3rd) CVE-2026-33186 2026-04-15 - --------------------------BEGIN INCLUDED TEXT-------------------- RHSA-2026:7245 - Security Advisory Issued: 2026-04-15 Updated: 2026-04-15 Synopsis Container platform 4.21.10 bug fix and security update Type/Severity Security Advisory: Important Topic Red Hat OpenShift Container Platform release 4.21.10 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 4.21.10. See the following advisory for the RPM packages for this release: https://access.redhat.com/errata/RHBA-2026:7240 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 sha256:5d591a70c92a6dfa3b6b948ffe5e5eac7ab339c49005744006aa0dd9d6d98898 (For s390x architecture) The image digest is sha256:57ce8750af38a4b2fe4cb8ebde95968daec9a565f81f613ddc279c1bf4917a26 (For ppc64le architecture) The image digest is sha256:43ad23cfd2db3851e66823a24333ebbf638e223b89d2610011a2e36a4ead977d (For aarch64 architecture) The image digest is sha256:e5987c2c35e6b6bd597332fc795ef6ea25114e8563e7fb8e2dbde788dd3e4ca0 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. Fixes o BZ - 2449833 o OCPBUGS-70213 - Using agent based install of 2 nodes with arbiter complets the bootstrap step but does not move forward o OCPBUGS-76269 - olm ClusterOperator relatedObjects missing ClusterRole o OCPBUGS-77966 - [release-4.21] global-pull-secret-syncer pod ~15-minute delay scheduling on new nodes o OCPBUGS-78991 - Bump Kubernetes v1.34.6 to release-4.21 o OCPBUGS-81145 - 4.21 - Extreme CPU Usage observed from Kubernetes components due to golang-fips TLS1.3 handling o OCPBUGS-81645 - CLONE - OVE ISO operator versions need updating CVEs o CVE-2026-33186 References o https://access.redhat.com/security/updates/classification/ - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://portal.auscert.org.au/bulletins/ =========================================================================== AUSCERT The University of Queensland, Brisbane QLD 4072 Australia e: auscert@auscert.org.au t: +61 (0)7 3365 4417 Allies in Cyber Security ===========================================================================

Risk Scores

CVSS v3.1

8.100000381469727

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected Products

Vendor	Product	Versions
Red Hat	OpenShift Container Platform 4.21.10

Timeline

Apr 16, 2026 CVE Published
Apr 16, 2026 Distribution Patch

References

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