RHSA-2026:87374 - Security Advisory

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: ipv4: raw: reject IP_HDRINCL packets with ihl < 5 (CVE-2026-64114)
• kernel: fuse: re-lock request before returning from fuse_ref_folio() (CVE-2026-64266)
• kernel: ipv4: fib: free fib_alias with kfree_rcu() on insert error path (CVE-2026-64572)
• kernel: ALSA: seq: close a re-opened queue timer in the destructor (CVE-2026-68202)
• kernel: xfs: bounds-check buffer log item's dirty bitmap (CVE-2026-80536)
• kernel: inet: frags: strip GSO state from fragments before reassembly (CVE-2026-80590)
• kernel: vfio/pci: clear vdev->msi_perm after freeing it on init failure (CVE-2026-89777)

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.

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.

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 - 2502486 - CVE-2026-64114 kernel: ipv4: raw: reject IP_HDRINCL packets with ihl < 5
• BZ - 2507098 - CVE-2026-64266 kernel: fuse: re-lock request before returning from fuse_ref_folio()
• BZ - 2511413 - CVE-2026-64572 kernel: ipv4: fib: free fib_alias with kfree_rcu() on insert error path
• BZ - 2513245 - CVE-2026-68202 kernel: ALSA: seq: close a re-opened queue timer in the destructor
• BZ - 2524501 - CVE-2026-80536 kernel: xfs: bounds-check buffer log item's dirty bitmap
• BZ - 2525413 - CVE-2026-80590 kernel: inet: frags: strip GSO state from fragments before reassembly
• BZ - 2535066 - CVE-2026-89777 kernel: vfio/pci: clear vdev->msi_perm after freeing it on init failure

CVEs

• CVE-2026-64114
• CVE-2026-64266
• CVE-2026-64572
• CVE-2026-68202
• CVE-2026-80536
• CVE-2026-80590
• CVE-2026-89777

References

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