RHSA-2026:39984 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: rtmutex: Use waiter::task instead of current in remove_waiter() (CVE-2026-43499)
• kernel: futex/requeue: Prevent NULL pointer dereference in remove_waiter() on self-deadlock (CVE-2026-53166)
• 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 x86_64 - Extended Life Cycle Long Life 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2480453 - CVE-2026-43499 kernel: rtmutex: Use waiter::task instead of current in remove_waiter()
• BZ - 2492805 - CVE-2026-53166 kernel: futex/requeue: Prevent NULL pointer dereference in remove_waiter() on self-deadlock
• BZ - 2498915 - kernel: XFS data corruption using reflink

CVEs

• CVE-2026-43499
• CVE-2026-53166
• CVE-2026-64600

References

• https://access.redhat.com/security/updates/classification/#important