This Red Hat security advisory addresses three kernel-rt vulnerabilities for RHEL 8, including a high-severity flaw in the xfrm subsystem (CVE-2026-46116, CVSS 7.8) that could allow a local attacker to cause a denial-of-service, and a medium-severity issue in the bridge networking code (CVE-2026-46086, CVSS 5.5). The underlying kernel vulnerabilities affect a wide range of upstream Linux kernel versions, as detailed in the NVD data. The fix requires applying the provided kernel-rt update and rebooting the affected systems.
Red Hat Product Errata RHSA-2026:39180 - Security Advisory Issued: 2026-07-14 Updated: 2026-07-14 RHSA-2026:39180 - Security Advisory Overview Updated Packages Synopsis Important: kernel-rt security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for kernel-rt is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): kernel: net: bridge: use a stable FDB dst snapshot in RCU readers (CVE-2026-46086) kernel: xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete (CVE-2026-46116) kernel: XFS data corruption using reflink () For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution 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. Affected Products Red Hat Enterprise Linux for Real Time 8 x86_64 Red Hat Enterprise Linux for Real Time for NFV 8 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64 Fixes BZ - 2481989 - CVE-2026-46086 kernel: net: bridge: use a stable FDB dst snapshot in RCU readers BZ - 2482523 - CVE-2026-46116 kernel: xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete BZ - 2498915 - kernel: XFS data corruption using reflink CVEs CVE-2026-46086 CVE-2026-46116 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. 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