RHSA-2026:21556HighCVSS 7.8

Red Hat Security Advisory: kernel security update

Published
May 28, 2026
Last Modified
July 30, 2026

🔗 CVE IDs covered (20)

CVE-2025-38653 →CVE-2025-68183 →CVE-2025-71089 →CVE-2026-23455 →CVE-2026-31685 →CVE-2026-31709 →CVE-2026-43110 →CVE-2026-46195 →CVE-2026-31684 →CVE-2026-43190 →CVE-2026-43027 →CVE-2026-31408 →CVE-2026-43020 →CVE-2026-43051 →CVE-2025-68366 →CVE-2025-68724 →CVE-2026-23392 →CVE-2026-43023 →CVE-2026-43158 →CVE-2026-43303 →

📋 Description

CVE-2025-38653 — kernel: proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al CVE-2025-68183 — kernel: ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr CVE-2025-68366 — kernel: nbd: defer config unlock in nbd_genl_connect CVE-2025-68724 — kernel: crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id CVE-2025-71089 — kernel: iommu: disable SVA when CONFIG_X86 is set CVE-2026-23392 — kernel: netfilter: nf_tables: release flowtable after rcu grace period on error CVE-2026-23455 — kernel: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() CVE-2026-31408 — kernel: Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold CVE-2026-31684 — kernel: net: sched: act_csum: validate nested VLAN headers CVE-2026-31685 — kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets CVE-2026-31709 — kernel: smb: client: validate the whole DACL before rewriting it in cifsacl CVE-2026-43020 — kernel: Bluetooth: MGMT: validate LTK enc_size on load CVE-2026-43023 — kernel: Bluetooth: SCO: fix race conditions in sco_sock_connect() CVE-2026-43027 — kernel: netfilter: nf_conntrack_helper: pass helper to expect cleanup CVE-2026-43051 — kernel: HID: wacom: fix out-of-bounds read in wacom_intuos_bt_irq CVE-2026-43110 — kernel: wifi: brcmfmac: validate bsscfg indices in IF events CVE-2026-43158 — kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks CVE-2026-43190 — kernel: netfilter: xt_tcpmss: check remaining length before reading optlen CVE-2026-43303 — kernel: mm/page_alloc: clear page->private in free_pages_prepare() CVE-2026-46195 — kernel: smb: client: validate dacloffset before building DACL pointers

🎯 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-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.12.1.el9_8.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.12.1.el9_8.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.12.1.el9_8.src as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-0:5.14.0-687.12.1.el9_8.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-core-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-core-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • kernel-64k-debug-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 9)
  • kernel-64k-debug-devel-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-devel-matched-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debug-modules-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-modules-core-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debug-modules-extra-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • kernel-64k-debuginfo-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux Real Time (v. 9)
  • kernel-64k-devel-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-devel-matched-0:5.14.0-687.12.1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • kernel-64k-modules-0:5.14.0-687.12.1.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. Workaround: To mitigate this issue, if SMB client functionality is not required, the `cifs` kernel module can be blacklisted to prevent it from loading. This can be achieved by creating a modprobe configuration file. 1. Create a file named `/etc/modprobe.d/disable-cifs.conf` with the following content: ``` install cifs /bin/true blacklist cifs ``` 2. Regenerate the initramfs to ensure the change takes effect on boot: ```bash dracut -f -v ``` or for systems using `mkinitrd`: ```bash mkinitrd -f /boot/initramfs-$(uname -r).img $(uname -r) ``` 3. A system reboot is required for the changes to take effect. Warning: Disabling the `cifs` module will prevent the system from mounting SMB/CIFS shares. Ensure this functionality is not critical before applying this mitigation. refer: https://access.redhat.com/solutions/4117281 Workaround: To mitigate this issue, prevent module brcmfmac 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: Mitigation for this issue is either not available or the currently available options don't 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, avoid mounting shares from untrusted SMB servers on 32-bit Red Hat Enterprise Linux systems. If interaction with untrusted SMB servers is unavoidable, consider isolating affected systems or restricting network access to only known, trusted SMB servers.

🔗 References (22)