RHSA-2026:91639HighCVSS 8.3

Red Hat Security Advisory: kpatch-patch-5_14_0-427_100_1, kpatch-patch-5_14_0-427_113_1, kpatch-patch-5_14_0-427_126_1, kpatch-patch-5_14_0-427_146_1, and kpatch-patch-5_14_0-427_84_1 security update

Published
October 28, 2026
Last Modified
October 31, 2026

🔗 CVE IDs covered (5)

CVE-2026-53266 →CVE-2026-68121 →CVE-2026-74480 →CVE-2026-74582 →CVE-2026-80844 →

📋 Description

CVE-2026-53266 — kernel: netfilter: ebtables SNAT target writes to shared memory pages during ARP hardware address rewrite CVE-2026-68121 — kernel: pppoe: reload header pointer after dev_hard_header() CVE-2026-74480 — kernel: net: bridge: stop fast-leave after deleting a port group CVE-2026-74582 — kernel: packet: use consistent hard_header_len in non-ring send paths CVE-2026-80844 — kernel: xfrm: ah6: validate routing header segments_left

🎯 Affected products36

  • Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-0:1-17.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-0:1-17.el9_4.src as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-0:1-17.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-debuginfo-0:1-17.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-debuginfo-0:1-17.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-debugsource-0:1-17.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_100_1-debugsource-0:1-17.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-0:1-15.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-0:1-15.el9_4.src as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-0:1-15.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-debuginfo-0:1-15.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-debuginfo-0:1-15.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-debugsource-0:1-15.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_113_1-debugsource-0:1-15.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-0:1-12.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-0:1-12.el9_4.src as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-0:1-12.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-debuginfo-0:1-12.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-debuginfo-0:1-12.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-debugsource-0:1-12.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_126_1-debugsource-0:1-12.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-0:1-3.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-0:1-3.el9_4.src as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-0:1-3.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-debuginfo-0:1-3.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-debuginfo-0:1-3.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-debugsource-0:1-3.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_146_1-debugsource-0:1-3.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kpatch-patch-5_14_0-427_84_1-0:1-19.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • +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 Workaround: Disable ARP hardware address rewriting in ebtables SNAT rules, or remove ebtables SNAT rules that operate on ARP traffic on bridge interfaces. Workaround: See the security bulletin for a detailed mitigation procedure. Workaround: If bridge multicast snooping is not required, it can be disabled to prevent the vulnerable code path from being reached: ``` echo 0 > /sys/class/net/<bridge>/bridge/multicast_snooping ``` The br_multicast_leave_group() code path is only reachable when multicast snooping is active, so disabling it eliminates exposure to this flaw. Alternatively, avoid toggling multicast_to_unicast on bridge ports after it has been enabled. If multicast snooping is required, ensure that multicast_to_unicast is either left at its default (disabled) or, once enabled on a port, is not subsequently disabled while the port has active multicast group memberships.

🔗 References (8)