RHSA-2026:23237 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.

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: net: use dst_dev_rcu() in sk_setup_caps() (CVE-2025-40170)
• kernel: ipv6: use RCU in ip6_xmit() (CVE-2025-40135)
• kernel: ipv6: use RCU in ip6_output() (CVE-2025-40158)
• kernel: crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id (CVE-2025-68724)
• kernel: iommu: disable SVA when CONFIG_X86 is set (CVE-2025-71089)
• kernel: scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count() (CVE-2026-23216)
• kernel: netfilter: nf_tables: release flowtable after rcu grace period on error (CVE-2026-23392)
• kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets (CVE-2026-31685)
• kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037)
• kernel: ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach() (CVE-2026-43038)
• kernel: smb: client: validate the whole DACL before rewriting it in cifsacl (CVE-2026-31709)
• kernel: wifi: brcmfmac: validate bsscfg indices in IF events (CVE-2026-43110)

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 9.4 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 s390x

Fixes

• BZ - 2414506 - CVE-2025-40170 kernel: net: use dst_dev_rcu() in sk_setup_caps()
• BZ - 2414521 - CVE-2025-40135 kernel: ipv6: use RCU in ip6_xmit()
• BZ - 2414523 - CVE-2025-40158 kernel: ipv6: use RCU in ip6_output()
• BZ - 2424886 - CVE-2025-68724 kernel: crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id
• BZ - 2429104 - CVE-2025-71089 kernel: iommu: disable SVA when CONFIG_X86 is set
• BZ - 2440630 - CVE-2026-23216 kernel: scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count()
• BZ - 2451218 - CVE-2026-23392 kernel: netfilter: nf_tables: release flowtable after rcu grace period on error
• BZ - 2461759 - CVE-2026-31685 kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets
• BZ - 2464351 - CVE-2026-43037 kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err()
• BZ - 2464397 - CVE-2026-43038 kernel: ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach()
• BZ - 2464476 - CVE-2026-31709 kernel: smb: client: validate the whole DACL before rewriting it in cifsacl
• BZ - 2467014 - CVE-2026-43110 kernel: wifi: brcmfmac: validate bsscfg indices in IF events

CVEs

• CVE-2025-40135
• CVE-2025-40158
• CVE-2025-40170
• CVE-2025-68724
• CVE-2025-71089
• CVE-2026-23216
• CVE-2026-23392
• CVE-2026-31685
• CVE-2026-31709
• CVE-2026-43037
• CVE-2026-43038
• CVE-2026-43110

References

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