Red Hat Security Advisory: OpenShift Container Platform 4.20.25 bug fix and security update
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/ Security Fix(es): * kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. 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.
AI Analysis
Technical Summary
CVE-2026-43037 is a critical kernel vulnerability in the ip6_tunnel component where the skb2->cb[] field is not properly cleared in the ip4ip6_err() function. This issue affects Red Hat Enterprise Linux 9 and 10 kernel versions targeted by the kpatch live patch modules (kernel-5.14.0-687.10.1.el9_8 and kernel-6.12.0-211.16.1.el10_2). Red Hat has issued security advisories RHSA-2026:28741 and RHSA-2026:28742 providing updated kpatch modules to fix this vulnerability. The advisories include detailed instructions for applying the live patches to running kernels without rebooting. The vulnerability is tracked under CWE-787 and CWE-843. No active exploitation has been reported.
Potential Impact
The vulnerability affects the kernel's ip6_tunnel functionality, potentially leading to undefined behavior due to improper clearing of skb2->cb[]. Red Hat rates this issue as critical, indicating a significant security impact if exploited. However, no known exploits in the wild have been reported to date. The impact details are limited to the kernel component and do not specify exact attack vectors or outcomes in the provided data.
Mitigation Recommendations
Red Hat has released official kernel live patch modules (kpatch-patch-5_14_0-687_10_1 for RHEL 9 and kpatch-patch-6_12_0-211_16_1 for RHEL 10) that address CVE-2026-43037. Users should apply these live patches following Red Hat's documented procedures to remediate the vulnerability without requiring system reboot. For detailed patch application instructions, refer to https://access.redhat.com/articles/11258. The patches are available through Red Hat's errata advisories RHSA-2026:28741 and RHSA-2026:28742. Applying these updates is the recommended and effective mitigation.
Red Hat Security Advisory: OpenShift Container Platform 4.20.25 bug fix and security update
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/ Security Fix(es): * kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. 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 software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-43037 is a critical kernel vulnerability in the ip6_tunnel component where the skb2->cb[] field is not properly cleared in the ip4ip6_err() function. This issue affects Red Hat Enterprise Linux 9 and 10 kernel versions targeted by the kpatch live patch modules (kernel-5.14.0-687.10.1.el9_8 and kernel-6.12.0-211.16.1.el10_2). Red Hat has issued security advisories RHSA-2026:28741 and RHSA-2026:28742 providing updated kpatch modules to fix this vulnerability. The advisories include detailed instructions for applying the live patches to running kernels without rebooting. The vulnerability is tracked under CWE-787 and CWE-843. No active exploitation has been reported.
Potential Impact
The vulnerability affects the kernel's ip6_tunnel functionality, potentially leading to undefined behavior due to improper clearing of skb2->cb[]. Red Hat rates this issue as critical, indicating a significant security impact if exploited. However, no known exploits in the wild have been reported to date. The impact details are limited to the kernel component and do not specify exact attack vectors or outcomes in the provided data.
Mitigation Recommendations
Red Hat has released official kernel live patch modules (kpatch-patch-5_14_0-687_10_1 for RHEL 9 and kpatch-patch-6_12_0-211_16_1 for RHEL 10) that address CVE-2026-43037. Users should apply these live patches following Red Hat's documented procedures to remediate the vulnerability without requiring system reboot. For detailed patch application instructions, refer to https://access.redhat.com/articles/11258. The patches are available through Red Hat's errata advisories RHSA-2026:28741 and RHSA-2026:28742. Applying these updates is the recommended and effective mitigation.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:25534
- Cve Count
- 1
- Cvss Version
- 3.1
Threat ID: 6a2d2f88e617e2d834b6e516
Added to database: 06/13/2026, 10:23:04 UTC
Last enriched: 08/11/2026, 20:35:22 UTC
Last updated: 09/14/2026, 22:01:34 UTC
Views: 1015
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