RHSA-2026:95100 - 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: sctp: stream: fully roll back denied add-stream state (CVE-2026-52929)
• kernel: net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket (CVE-2026-64541)
• kernel: sctp: clear new_transport when removing a peer (CVE-2026-74586)
• kernel: RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp (CVE-2026-80864)
• kernel: RDMA/rxe: Fix OOB in free_rd_atomic_resources() (CVE-2026-80863)
• kernel: openvswitch: Fix CT limit teardown use-after-free (CVE-2026-89488)

Bug Fix(es) and Enhancement(s):

• RHEL8.10 - s390/smp: Remove conditional emergency signal usage (JIRA:RHEL-298849)

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 - 2492108 - CVE-2026-52929 kernel: sctp: stream: fully roll back denied add-stream state
• BZ - 2507721 - CVE-2026-64541 kernel: net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket
• BZ - 2521419 - CVE-2026-74586 kernel: sctp: clear new_transport when removing a peer
• BZ - 2528646 - CVE-2026-80864 kernel: RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp
• BZ - 2528665 - CVE-2026-80863 kernel: RDMA/rxe: Fix OOB in free_rd_atomic_resources()
• BZ - 2532407 - CVE-2026-89488 kernel: openvswitch: Fix CT limit teardown use-after-free

CVEs

• CVE-2026-52929
• CVE-2026-64541
• CVE-2026-74586
• CVE-2026-80863
• CVE-2026-80864
• CVE-2026-89488

References

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