RHSA-2026:26570 — Security Advisory

An update for kernel is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On.

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.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: geneve: Fix use-after-free in geneve_find_dev(). (CVE-2025-21858)

• kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800)

• kernel: Linux kernel: Denial of service and memory corruption in RDMA umad (CVE-2026-23243)

• kernel: netfilter: nf_tables: release flowtable after rcu grace period on error (CVE-2026-23392)

• kernel: netfilter: ctnetlink: ensure safe access to master conntrack (CVE-2026-43116)

• kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks (CVE-2026-43158)

• kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243)

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.