RHSA-2026:66180HighCVSS 8.1

Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Published
September 10, 2026
Last Modified
September 15, 2026

🔗 CVE IDs covered (17)

CVE-2026-46015 →CVE-2026-46306 →CVE-2026-43133 →CVE-2026-43339 →CVE-2026-46266 →CVE-2026-53002 →CVE-2026-53223 →CVE-2026-53366 →CVE-2026-46149 →CVE-2026-53275 →CVE-2026-64597 →CVE-2026-74480 →CVE-2026-43493 →CVE-2026-46330 →CVE-2026-64034 →CVE-2026-64563 →CVE-2026-72129 →

📋 Description

CVE-2026-43133 — kernel: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation CVE-2026-43339 — kernel: ipv6: prevent possible UaF in addrconf_permanent_addr() CVE-2026-43493 — kernel: crypto: pcrypt - Fix handling of MAY_BACKLOG requests CVE-2026-46015 — kernel: tcp: call sk_data_ready() after listener migration CVE-2026-46149 — kernel: scsi: target: configfs: Bound snprintf() return in tg_pt_gp_members_show() CVE-2026-46266 — kernel: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP CVE-2026-46306 — kernel: flow_dissector: do not dissect PPPoE PFC frames CVE-2026-46330 — kernel: Revert "net/smc: Introduce TCP ULP support" CVE-2026-53002 — kernel: netfilter: conntrack: remove sprintf usage CVE-2026-53223 — kernel: net: guard timestamp cmsgs to real error queue skbs CVE-2026-53275 — kernel: ipv6: mcast: Fix use-after-free when processing MLD queries CVE-2026-53366 — kernel: ipv4: account for fraggap on the paged allocation path CVE-2026-64034 — kernel: net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer CVE-2026-64563 — kernel: rhashtable: clear stale iter->p on table restart CVE-2026-64597 — kernel: smb: client: fix double-free in SMB2_close() replay 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 products200

  • Red Hat Enterprise Linux AppStream (v. 9)
  • Red Hat Enterprise Linux BaseOS (v. 9)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • Red Hat Enterprise Linux Real Time (v. 9)
  • Red Hat Enterprise Linux Real Time for NFV (v. 9)
  • kernel-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.46.1.el9_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.46.1.el9_8.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.46.1.el9_8.src as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.46.1.el9_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-core-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-core-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 9)
  • kernel-64k-debug-devel-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-devel-matched-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-modules-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-modules-core-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-modules-extra-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 9)
  • kernel-64k-devel-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-devel-matched-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-modules-0:5.14.0-687.46.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • +170 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: 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 module smc from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically. 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: If SMB/CIFS client functionality is not required, the 'cifs' kernel module can be blocklisted to prevent it from loading. Systems that do not mount SMB/CIFS shares are not affected. For systems that require SMB client access, ensure connections are only made to trusted SMB servers. 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 (20)