RHSA-2026:64770HighCVSS 8.1

Red Hat Security Advisory: kernel-rt security update

Published
September 8, 2026
Last Modified
September 8, 2026

🔗 CVE IDs covered (7)

CVE-2026-43493 →CVE-2026-53002 →CVE-2026-64007 →CVE-2026-64563 →CVE-2026-68343 →CVE-2026-72129 →CVE-2026-74480 →

📋 Description

CVE-2026-43493 — kernel: crypto: pcrypt - Fix handling of MAY_BACKLOG requests CVE-2026-53002 — kernel: netfilter: conntrack: remove sprintf usage CVE-2026-64007 — kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable CVE-2026-64563 — kernel: rhashtable: clear stale iter->p on table restart CVE-2026-68343 — kernel: smb: client: validate DFS referral PathConsumed CVE-2026-72129 — kernel: nvmet-rdma: handle inline data with a nonzero offset CVE-2026-74480 — kernel: net: bridge: stop fast-leave after deleting a port group

🎯 Affected products32

  • Red Hat Enterprise Linux NFV (v. 8)
  • Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-0:4.18.0-553.160.1.rt7.501.el8_10.src as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-0:4.18.0-553.160.1.rt7.501.el8_10.src as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-core-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-core-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-core-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-core-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-debuginfo-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-debuginfo-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-devel-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-devel-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-kvm-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-modules-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-modules-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debug-modules-extra-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debug-modules-extra-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debuginfo-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debuginfo-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-debuginfo-common-x86_64-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-debuginfo-common-x86_64-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-devel-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-devel-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • kernel-rt-kvm-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-modules-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux NFV (v. 8)
  • kernel-rt-modules-0:4.18.0-553.160.1.rt7.501.el8_10.x86_64 as a component of Red Hat Enterprise Linux RT (v. 8)
  • +2 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 nf_conntrack_sip and nf_nat_sip modules from being loaded. See https://access.redhat.com/solutions/41278 for instructions. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Workaround: To mitigate this issue, prevent the `nvmet_rdma` kernel module from loading if NVMe over RDMA functionality is not required. This can be achieved by creating a modprobe configuration file. 1. Create a file named `/etc/modprobe.d/disable-nvmet_rdma.conf` with the following content: ``` install nvmet_rdma /bin/true ``` 2. Regenerate the initramfs to ensure the change takes effect on boot: ```bash dracut -f -v ``` 3. Reboot the system for the changes to be fully applied. This mitigation may impact systems that rely on NVMe over RDMA for storage operations. If NVMe over RDMA is in use, consider configuring `inline_data_size` to be less than or equal to `PAGE_SIZE` if your workload permits, though this might affect performance. 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 (10)