RHSA-2026:53989HighCVSS 8.1

Red Hat Security Advisory: kernel security update

Published
August 12, 2026
Last Modified
October 30, 2026

🔗 CVE IDs covered (4)

CVE-2026-31787 →CVE-2026-43112 →CVE-2026-43163 →CVE-2026-53059 →

📋 Description

CVE-2026-31787 — kernel: xen/privcmd: fix double free via VMA splitting CVE-2026-43112 — kernel: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath CVE-2026-43163 — kernel: md/bitmap: fix GPF in write_page caused by resize race CVE-2026-53059 — kernel: dm log: fix out-of-bounds write due to region_count overflow

🎯 Affected products52

  • Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • bpftool-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • bpftool-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • bpftool-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • bpftool-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-0:4.18.0-372.206.1.el8_6.src as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-0:4.18.0-372.206.1.el8_6.src as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-abi-stablelists-0:4.18.0-372.206.1.el8_6.noarch as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-abi-stablelists-0:4.18.0-372.206.1.el8_6.noarch as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-core-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-core-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-core-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-core-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-devel-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-devel-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-modules-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-modules-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debug-modules-extra-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debug-modules-extra-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debuginfo-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • kernel-debuginfo-common-x86_64-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • kernel-debuginfo-common-x86_64-0:4.18.0-372.206.1.el8_6.x86_64 as a component of Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • +22 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. Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture. Because of this proactive approach, a patch may be associated with a CVE assignment at a future date. Retroactive CVE assignments are always documented in the corresponding errata and on Red Hat's CVE pages. We strongly advise against delaying updates, as doing so may leave your system exposed when protections are already available. Workaround: To mitigate this issue, prevent the `privcmd` kernel module from loading if Xen virtualization is not actively used on the system. This can be achieved by blacklisting the module. Create a file named `/etc/modprobe.d/blacklist-privcmd.conf` with the following content: `blacklist privcmd` After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. `dracut -f -v` (for RHEL 7/8/9) or `mkinitrd -f -v` (for older RHEL versions) `reboot` This mitigation will prevent the `privcmd` module from being loaded at boot, thereby eliminating the vulnerability. However, systems requiring Xen virtualization will lose `privcmd` functionality. Workaround: To mitigate this issue, prevent the `cifs` kernel module from loading if CIFS client functionality is not required. This can be achieved by blacklisting the module. Create a file named `/etc/modprobe.d/blacklist-cifs.conf` with the following content: ``` blacklist cifs ``` After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. ```bash dracut -f -v reboot ``` Disabling the `cifs` module will prevent the system from mounting CIFS network shares, which may impact functionality relying on this protocol.

🔗 References (8)