RHSA-2026:79783 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 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: Linux kernel: xfrm single-frag length not properly limited ()
• kernel: scsi: target: configfs: Bound snprintf() return in tg_pt_gp_members_show() (CVE-2026-46149)
• kernel: blk-cgroup: fix UAF in __blkcg_rstat_flush() (CVE-2026-63802)
• kernel: udp: fix potential use-after-free in tunnel segmentation (CVE-2026-74705)

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 x86_64 - Extended Life Cycle Long Life 8.6 x86_64
• Red Hat Enterprise Linux Server - AUS 8.6 x86_64

Fixes

• BZ - 2482566 - CVE-2026-46149 kernel: scsi: target: configfs: Bound snprintf() return in tg_pt_gp_members_show()
• BZ - 2502251 - CVE-2026-63802 kernel: blk-cgroup: fix UAF in __blkcg_rstat_flush()
• BZ - 2521498 - CVE-2026-74705 kernel: udp: fix potential use-after-free in tunnel segmentation

CVEs

• CVE-2026-46149
• CVE-2026-63802
• CVE-2026-74705

References

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