Red Hat Security Advisory: OpenShift Container Platform 4.21.34 packages 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 RPM packages for Red Hat OpenShift Container Platform 4.21.34. See the following advisory for the container images for this release: https://access.redhat.com/errata/RHSA-2026:68546 Security Fix(es): * crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages (CVE-2026-56862) 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
This advisory covers a denial of service vulnerability in the Golang crypto/tls package used by Red Hat OpenShift Container Platform 4.21. The vulnerability (CVE-2026-56862) allows denial of service via indefinite KeyUpdate messages. Red Hat has released updated RPM packages and container images in version 4.21.34 to address this issue. The update is recommended for all OpenShift Container Platform 4.21 users and includes instructions for upgrading clusters. The advisory references Red Hat's errata RHSA-2026:68538 for RPM packages and RHSA-2026:68546 for container images.
Potential Impact
The vulnerability allows an attacker to cause a denial of service condition by sending indefinite KeyUpdate messages to the Golang crypto/tls implementation used in OpenShift Container Platform. This could disrupt the availability of affected systems. No known exploits in the wild have been reported. The security impact is rated as important by Red Hat.
Mitigation Recommendations
A fix is available in Red Hat OpenShift Container Platform 4.21.34 packages and container images. Users should upgrade to these updated packages and images as soon as they are available in their release channel. Upgrades can be performed using the OpenShift CLI (oc) or the web console. Detailed upgrade instructions are provided in Red Hat's official documentation. No additional mitigation steps are indicated beyond applying the update.
Red Hat Security Advisory: OpenShift Container Platform 4.21.34 packages 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 RPM packages for Red Hat OpenShift Container Platform 4.21.34. See the following advisory for the container images for this release: https://access.redhat.com/errata/RHSA-2026:68546 Security Fix(es): * crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages (CVE-2026-56862) 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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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory covers a denial of service vulnerability in the Golang crypto/tls package used by Red Hat OpenShift Container Platform 4.21. The vulnerability (CVE-2026-56862) allows denial of service via indefinite KeyUpdate messages. Red Hat has released updated RPM packages and container images in version 4.21.34 to address this issue. The update is recommended for all OpenShift Container Platform 4.21 users and includes instructions for upgrading clusters. The advisory references Red Hat's errata RHSA-2026:68538 for RPM packages and RHSA-2026:68546 for container images.
Potential Impact
The vulnerability allows an attacker to cause a denial of service condition by sending indefinite KeyUpdate messages to the Golang crypto/tls implementation used in OpenShift Container Platform. This could disrupt the availability of affected systems. No known exploits in the wild have been reported. The security impact is rated as important by Red Hat.
Mitigation Recommendations
A fix is available in Red Hat OpenShift Container Platform 4.21.34 packages and container images. Users should upgrade to these updated packages and images as soon as they are available in their release channel. Upgrades can be performed using the OpenShift CLI (oc) or the web console. Detailed upgrade instructions are provided in Red Hat's official documentation. No additional mitigation steps are indicated beyond applying the update.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:68538
- Cve Count
- 1
- State
- PUBLISHED
Threat ID: 6ab4be15f7a7c54106eee3c1
Added to database: 09/24/2026, 06:07:17 UTC
Last enriched: 09/24/2026, 06:10:37 UTC
Last updated: 09/25/2026, 04:51:38 UTC
Views: 7
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