RHSA-2026:27719CriticalCVSS 8.8

Red Hat Security Advisory: kernel security update

Published
June 22, 2026
Last Modified
August 6, 2026

🔗 CVE IDs covered (2)

CVE-2026-43037 →CVE-2026-46243 →

📋 Description

CVE-2026-43037 — kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() CVE-2026-46243 — kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions

🎯 Affected products58

  • Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-0:2.6.32-754.61.1.el6.src as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-abi-whitelists-0:2.6.32-754.61.1.el6.noarch as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-debuginfo-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debug-devel-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-devel-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debug-devel-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debuginfo-common-i686-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-common-i686-0:2.6.32-754.61.1.el6.i686 as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debuginfo-common-s390x-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • kernel-debuginfo-common-s390x-0:2.6.32-754.61.1.el6.s390x as a component of Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)
  • kernel-debuginfo-common-x86_64-0:2.6.32-754.61.1.el6.x86_64 as a component of Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • +28 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: Mitigation for this issue is to skip loading the affected module `ip6_tunnel` onto the system till we have a fix available, this can be done by a blacklist mechanism, this will ensure the driver is not loaded at the boot time. ~~~ How do I blacklist a kernel module to prevent it from loading automatically? https://access.redhat.com/solutions/41278 ~~~ We may also want to detection and monitoring an affected system as below: ~~~ Monitor for exploitation attempts: # Enable kernel audit for IPv6 tunnel operations auditctl -a always,exit -F arch=b64 -S socket -F a0=10 -F a1=3 -k ipv6_tunnel # Monitor system logs for kernel panics/crashes journalctl -k -p err -f | grep -i "ip6_tunnel\|icmp\|stack" ~~~ Workaround: See the security bulletin for a detailed mitigation procedure.

🔗 References (5)