RHSA-2026:27735HighCVSS 8.7

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

Published
June 22, 2026
Last Modified
October 21, 2026

🔗 CVE IDs covered (11)

📋 Description

CVE-2025-30156 — kernel: ceph: kernel: Ceph: exploit of hardcoded IVECs, in a misuse of AES, resulting in authentication bypass CVE-2025-71116 — kernel: libceph: make decode_pool() more resilient against corrupted osdmaps CVE-2026-22984 — kernel: libceph: prevent potential out-of-bounds reads in handle_auth_done() CVE-2026-22990 — kernel: libceph: replace overzealous BUG_ON in osdmap_apply_incremental() CVE-2026-43116 — kernel: netfilter: ctnetlink: ensure safe access to master conntrack CVE-2026-43158 — kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks CVE-2026-43303 — kernel: mm/page_alloc: clear page->private in free_pages_prepare() CVE-2026-46125 — kernel: wifi: mac80211: remove station if connection prep fails CVE-2026-46227 — kernel: sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL CVE-2026-46243 — kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions CVE-2026-46323 — kernel: Linux kernel: Use-After-Free in net/gro due to improper handling of zerocopy skbs

🎯 Affected products200

  • Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • Red Hat Enterprise Linux Real Time E4S (v.9.4)
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)
  • bpftool-0:7.3.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-0:7.3.0-427.132.1.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-0:7.3.0-427.132.1.el9_4.s390x as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-0:7.3.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.ppc64le as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.s390x as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.s390x as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux Real Time E4S (v.9.4)
  • bpftool-debuginfo-0:7.3.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)
  • kernel-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-0:5.14.0-427.132.1.el9_4.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-0:5.14.0-427.132.1.el9_4.s390x as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-0:5.14.0-427.132.1.el9_4.src as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-0:5.14.0-427.132.1.el9_4.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-core-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-debug-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-debug-core-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-debug-debuginfo-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • kernel-64k-debug-debuginfo-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux BaseOS E4S (v.9.4)
  • kernel-64k-debug-devel-0:5.14.0-427.132.1.el9_4.aarch64 as a component of Red Hat Enterprise Linux AppStream E4S (v.9.4)
  • +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, Red Hat recommends isolating the Ceph messenger protocol to dedicated internal networks with strict access controls, limiting exposure to potential attackers. Administrators should audit and minimize the number of CephX client credentials in circulation and enforce strong credential management to reduce the risk of low-privilege key compromise. Where possible, deploy msgr2 with on-wire encryption to reduce passive sniffing exposure. It is strongly advised to apply vendor-supplied patches as soon as they are released, upgrade to fixed Ceph versions (Tentacle 20.2.4 or later), and rotate all CephX keys to the new AES-256-CTS-HMAC-SHA384-192 cipher type, prioritizing server-side keys. Workaround: To mitigate this issue and if Ceph not being used, then prevent module libceph 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: If Ceph not being used, then possible to disable it. To mitigate this issue, prevent module libceph 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 to skip loading the affected module "netfilter" 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 ~~~ 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 vulnerability on systems that do not require Wi-Fi connectivity, prevent the mac80211 kernel module from loading. 1. Blacklist the module by creating a configuration file in /etc/modprobe.d/: ``` echo "install mac80211 /bin/true" >> /etc/modprobe.d/disable-mac80211.conf ``` 2. If the module is currently loaded, unload it or restart the system: ``` modprobe -r mac80211 ``` Caveats: Disabling mac80211 disables all Wi-Fi functionality on the host. Unloading kernel modules or restarting the system will interrupt active network services and running workloads. If dependent wireless drivers are actively in use, a system reboot is required for the configuration to take effect. Workaround: To mitigate this issue, prevent module sctp 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: See the security bulletin for a detailed mitigation procedure. 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.

🔗 References (13)