RHSA-2026:54544HighCVSS 8.4

Red Hat Security Advisory: OpenShift Container Platform 4.18.53 bug fix and security update

Published
August 19, 2026
Last Modified
August 19, 2026

🔗 CVE IDs covered (3)

CVE-2025-5222 →CVE-2025-10263 →CVE-2025-40026 →

📋 Description

CVE-2025-5222 — icu: Stack buffer overflow in the SRBRoot::addTag function CVE-2025-10263 — kernel: Arm Processors: Privilege escalation or information disclosure via writes to higher exception level resources CVE-2025-40026 — kernel: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O

🎯 Affected products5

  • Red Hat OpenShift Container Platform 4.18
  • rhcos-aarch64-418.94.202608111829-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-ppc64le-418.94.202608111829-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-s390x-418.94.202608111829-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-x86_64-418.94.202608111829-0 as a component of Red Hat OpenShift Container Platform 4.18

✅ Remediation

For OpenShift Container Platform 4.18 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/4.18/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:f9d84ee7a22c2f9d1e36e40e7b2a06af7e14b44f5c88450d5567291d1b638dce (For s390x architecture) The image digest is sha256:b8422d0b0e94c96ab3d09f05702fcf318c4c94331671e7b845b37a4865cdd67e (For ppc64le architecture) The image digest is sha256:2c15d0c5237dc1a8553fc7e83d18f83ae7ac40f12397ac8017592802103b6d8a (For aarch64 architecture) The image digest is sha256:a316b38314a10b623db09bc4fd88fc74ccd8072e5cbcf6f5e19083b7e59ee28d All OpenShift Container Platform 4.18 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/4.18/html-single/updating_clusters/index#updating-cluster-cli. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Workaround: This vulnerability can be mitigated by disabling nested virtualization. Create a file in `/etc/modprobe.d/` with a descriptive name, such as `cve-2026-53359-mitigation.conf`. In that file, disable nested virtualization for the `kvm_intel` and `kvm_amd` kernel modules: ``` options kvm-intel nested=0 options kvm-amd nested=0 ``` Use `lsmod` to determine if either module is already loaded. If so, remove loaded modules with `modprobe -r`. To validate that nested virtualization is disabled, read the files `/sys/module/kvm_intel/parameters/nested` and `/sys/module/kvm_amd/parameters/nested`. If these modules are loaded, those files should read `N` to indicate that the feature is disabled. In OpenShift 4, a MachineConfig can be utilized to create a modprobe configuration allowing control of the module on applicable nodes. See the following article for an example. https://access.redhat.com/solutions/6979679

🔗 References (6)