RHSA-2026:9513 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.2 Advanced Update Support.

Red Hat Product Security has rated this update as having a security impact of Moderate. 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: smc: Fix use-after-free in __pnet_find_base_ndev() (CVE-2025-40064)
• kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match() (CVE-2025-40168)
• kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204)
• kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231)

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.

Affected Products

• Red Hat Enterprise Linux Server - AUS 8.2 x86_64

Fixes

• BZ - 2406747 - CVE-2025-40064 kernel: smc: Fix use-after-free in __pnet_find_base_ndev()
• BZ - 2414482 - CVE-2025-40168 kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match()
• BZ - 2439931 - CVE-2026-23204 kernel: net/sched: cls_u32: use skb_header_pointer_careful()
• BZ - 2444376 - CVE-2026-23231 kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain()

CVEs

• CVE-2025-40064
• CVE-2025-40168
• CVE-2026-23204
• CVE-2026-23231

References

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