RHSA-2026:85774 - 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: xfrm: espintcp: do not reuse an in-progress partial send (CVE-2026-52935)
• kernel: USB: serial: io_ti: fix heap overflow in get_manuf_info() (CVE-2026-53196)
• kernel: sctp: keep chunk->transport in step with the list it is queued on (CVE-2026-74588)
• kernel: sctp: validate cookie AUTH state before use (CVE-2026-74752)
• kernel: smb: client: reject a tree connect response whose byte count is too small (CVE-2026-89631)
• kernel: sctp: stop processing a packet once its association is deleted (CVE-2026-89479)
• kernel: perf: Fix addr_filter_ranges lifetime (CVE-2026-93817)
• kernel: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state (CVE-2026-93288)
• kernel: kernel: strparser: use-after-free via msg_timer_work rearm after strp_done() cancellation ()
• kernel: netfilter: flowtable: hold reference on ct until flow is released (CVE-2026-98320)

Bug Fix(es) and Enhancement(s):

• gfs2 filesystem withdrawal rework [RHEL-8] (JIRA:RHEL-129363)
• Batch: z-stream xfrm - rhel-8.10.z (NST-Core-26W38) (JIRA:RHEL-256684)

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 - 2492098 - CVE-2026-52935 kernel: xfrm: espintcp: do not reuse an in-progress partial send
• BZ - 2492750 - CVE-2026-53196 kernel: USB: serial: io_ti: fix heap overflow in get_manuf_info()
• BZ - 2521384 - CVE-2026-74588 kernel: sctp: keep chunk->transport in step with the list it is queued on
• BZ - 2524422 - CVE-2026-74752 kernel: sctp: validate cookie AUTH state before use
• BZ - 2532089 - CVE-2026-89631 kernel: smb: client: reject a tree connect response whose byte count is too small
• BZ - 2532290 - CVE-2026-89479 kernel: sctp: stop processing a packet once its association is deleted
• BZ - 2540391 - CVE-2026-93817 kernel: perf: Fix addr_filter_ranges lifetime
• BZ - 2540500 - CVE-2026-93288 kernel: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state
• BZ - 2540872 - kernel: kernel: strparser: use-after-free via msg_timer_work rearm after strp_done() cancellation
• BZ - 2546494 - CVE-2026-98320 kernel: netfilter: flowtable: hold reference on ct until flow is released

CVEs

• CVE-2026-52935
• CVE-2026-53196
• CVE-2026-74588
• CVE-2026-74752
• CVE-2026-89479
• CVE-2026-89631
• CVE-2026-93288
• CVE-2026-93817
• CVE-2026-98320

References

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