RHSA-2026:99133 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 10.

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: sctp: avoid auth_enable sysctl UAF during netns teardown (CVE-2026-68162)
• kernel: sctp: keep chunk->transport in step with the list it is queued on (CVE-2026-74588)
• kernel: sctp: clear new_transport when removing a peer (CVE-2026-74586)
• kernel: sctp: validate cookie AUTH state before use (CVE-2026-74752)
• kernel: mptcp: options: reset DSS fields in case of unexpected size (CVE-2026-80586)
• kernel: s390/vfio_ccw: Cancel existing workqueues (CVE-2026-80553)
• kernel: powerpc/pseries: papr-phy-attest - validate cmd.length, plug mem leak (CVE-2026-80571)
• kernel: s390/qeth: validate user buffer length in SNMP and ARP query ioctls (CVE-2026-80584)
• kernel: net/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link() (CVE-2026-80981)
• kernel: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() (CVE-2026-89633)
• kernel: sctp: stop processing a packet once its association is deleted (CVE-2026-89479)
• kernel: i3c: master: svc: bound IBI payload to the requested max_payload_len (CVE-2026-80951)
• kernel: s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects (CVE-2026-89956)
• kernel: ALSA: seq: midi: Serialize input teardown with event_input (CVE-2026-90207)
• kernel: smb: client: validate absolute native symlink targets before NT fixups (CVE-2026-98318)
• kernel: kernel: Denial of Service via unvalidated task in iSCSI management responses (CVE-2026-99152)
• kernel: kernel: Denial of service via unvalidated task tag in iSCSI Reject PDU (CVE-2026-99153)

Bug Fix(es) and Enhancement(s):

• mpls test multi_path fails on 10.3 CTC2 compose (JIRA:RHEL-222766)
• RHEL10.0 - kernel: CPU hotplug unsupported by CPUMF [rhel-10.3.z] (JIRA:RHEL-270889)
• Backport 6785011f8b16 ("ipv4: validate checksum_start before completing checksum") [rhel-10.3.z] (JIRA:RHEL-280591)

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 10 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for x86_64 10 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 10 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 10 s390x

Fixes

• BZ - 2513314 - CVE-2026-68162 kernel: sctp: avoid auth_enable sysctl UAF during netns teardown
• BZ - 2521384 - CVE-2026-74588 kernel: sctp: keep chunk->transport in step with the list it is queued on
• BZ - 2521419 - CVE-2026-74586 kernel: sctp: clear new_transport when removing a peer
• BZ - 2524422 - CVE-2026-74752 kernel: sctp: validate cookie AUTH state before use
• BZ - 2524438 - CVE-2026-80586 kernel: mptcp: options: reset DSS fields in case of unexpected size
• BZ - 2524442 - CVE-2026-80553 kernel: s390/vfio_ccw: Cancel existing workqueues
• BZ - 2524458 - CVE-2026-80571 kernel: powerpc/pseries: papr-phy-attest - validate cmd.length, plug mem leak
• BZ - 2524475 - CVE-2026-80584 kernel: s390/qeth: validate user buffer length in SNMP and ARP query ioctls
• BZ - 2532104 - CVE-2026-80981 kernel: net/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()
• BZ - 2532230 - CVE-2026-89633 kernel: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2()
• BZ - 2532290 - CVE-2026-89479 kernel: sctp: stop processing a packet once its association is deleted
• BZ - 2532522 - CVE-2026-80951 kernel: i3c: master: svc: bound IBI payload to the requested max_payload_len
• BZ - 2535200 - CVE-2026-89956 kernel: s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects
• BZ - 2536701 - CVE-2026-90207 kernel: ALSA: seq: midi: Serialize input teardown with event_input
• BZ - 2546374 - CVE-2026-98318 kernel: smb: client: validate absolute native symlink targets before NT fixups
• BZ - 2562697 - CVE-2026-99152 kernel: kernel: Denial of Service via unvalidated task in iSCSI management responses
• BZ - 2562706 - CVE-2026-99153 kernel: kernel: Denial of service via unvalidated task tag in iSCSI Reject PDU

CVEs

• CVE-2026-68162
• CVE-2026-74586
• CVE-2026-74588
• CVE-2026-74752
• CVE-2026-80553
• CVE-2026-80571
• CVE-2026-80584
• CVE-2026-80586
• CVE-2026-80951
• CVE-2026-80981
• CVE-2026-89479
• CVE-2026-89633
• CVE-2026-89956
• CVE-2026-90207
• CVE-2026-98318
• CVE-2026-99152
• CVE-2026-99153

References

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