RHSA-2026:59091: Important: kernel security update

Published Aug 24, 2026
·
Updated

Important: kernel security update

Other sources

The kernel packages contain the Linux kernel, the core of any Linux operating system.Security Fix(es): kernel: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O (CVE-2025-40026) kernel: dlm: validate length in dlmsearchrsbtree (CVE-2026-43125) kernel: xen: AMD Zen 2 Processors: Privilege escalation via improper CPU cache isolation (CVE-2025-54518) kernel: selinux: fix overlayfs mmap() and mprotect() access checks (CVE-2026-46054) 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.

— Red Hat

Affected Software

28 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux Server - AUS
redhat/kernel<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/bpftool<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/bpftool-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-abi-stablelists<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-core<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-cross-headers<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug-core<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug-devel<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug-modules<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debug-modules-extra<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-devel<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-doc<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-headers<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-modules<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-modules-extra<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-tools<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-tools-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/kernel-tools-libs<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/perf<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/perf-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/python3-perf<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4
redhat/python3-perf-debuginfo<4.18.0-305.201.1.el8_4
4.18.0-305.201.1.el8_4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  2. Upgrade

    Upgrade redhat/bpftool to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  3. Upgrade

    Upgrade redhat/bpftool-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  4. Upgrade

    Upgrade redhat/kernel-abi-stablelists to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  5. Upgrade

    Upgrade redhat/kernel-core to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  6. Upgrade

    Upgrade redhat/kernel-cross-headers to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  7. Upgrade

    Upgrade redhat/kernel-debug to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  8. Upgrade

    Upgrade redhat/kernel-debug-core to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  9. Upgrade

    Upgrade redhat/kernel-debug-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  10. Upgrade

    Upgrade redhat/kernel-debug-devel to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  11. Upgrade

    Upgrade redhat/kernel-debug-modules to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  12. Upgrade

    Upgrade redhat/kernel-debug-modules-extra to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  13. Upgrade

    Upgrade redhat/kernel-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  14. Upgrade

    Upgrade redhat/kernel-devel to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  15. Upgrade

    Upgrade redhat/kernel-doc to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  16. Upgrade

    Upgrade redhat/kernel-headers to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  17. Upgrade

    Upgrade redhat/kernel-modules to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  18. Upgrade

    Upgrade redhat/kernel-modules-extra to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  19. Upgrade

    Upgrade redhat/kernel-tools to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  20. Upgrade

    Upgrade redhat/kernel-tools-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  21. Upgrade

    Upgrade redhat/kernel-tools-libs to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  22. Upgrade

    Upgrade redhat/perf to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  23. Upgrade

    Upgrade redhat/perf-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  24. Upgrade

    Upgrade redhat/python3-perf to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  25. Upgrade

    Upgrade redhat/python3-perf-debuginfo to a version that resolves this vulnerability.

    Fixed in 4.18.0-305.201.1.el8_4
  26. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch CVE-2026-43125
  27. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch CVE-2026-46054
  28. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch CVE-2025-54518
  29. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch CVE-2025-40026
  30. Operational

    Reboot the system after applying the kernel security update so the changes in this advisory take effect.

Event History

Aug 24, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·02:20 PM
Data Sourced
via Red Hat·02:20 PM
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