Red Hat Security Advisory: kernel-rt security update
🔗 CVE IDs covered (5)
📋 Description
CVE-2026-43027 — kernel: netfilter: nf_conntrack_helper: pass helper to expect cleanup CVE-2026-43499 — kernel: rtmutex: Use waiter::task instead of current in remove_waiter() CVE-2026-46113 — kernel: KVM: x86: Fix shadow paging use-after-free due to unexpected GFN CVE-2026-53166 — kernel: futex/requeue: Prevent NULL pointer dereference in remove_waiter() on self-deadlock CVE-2026-53359 — kernel: KVM: x86: Fix shadow paging use-after-free due to unexpected role
🎯 Affected products36
- Red Hat Enterprise Linux Real Time E4S (v.9.2)
- Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-0:5.14.0-284.181.1.rt14.466.el9_2.src as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-0:5.14.0-284.181.1.rt14.466.el9_2.src as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-debuginfo-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-debuginfo-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-devel-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-devel-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-kvm-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-modules-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-modules-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-modules-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-modules-core-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debug-modules-extra-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debug-modules-extra-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debuginfo-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debuginfo-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-debuginfo-common-x86_64-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-debuginfo-common-x86_64-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-devel-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.2)
- kernel-rt-devel-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- kernel-rt-kvm-0:5.14.0-284.181.1.rt14.466.el9_2.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)
- +6 more not shown
✅ Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Workaround: See the security bulletin for a detailed mitigation procedure. Workaround: Mitigation for this issue is either not available or the currently available options don't 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 (8)
- selfhttps://access.redhat.com/errata/RHSA-2026:39983
- externalhttps://access.redhat.com/security/updates/classification/#moderate
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2464369
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2480453
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2482587
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2492805
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2497033
- selfhttps://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_39983.json