This Red Hat security advisory addresses seven Important-severity kernel vulnerabilities, including multiple use-after-free flaws in the GENEVE and mlxsw modules (CVE-2025-21858, CVSS 7.8), a denial-of-service and memory corruption issue in RDMA umad (CVE-2026-23243, CVSS 7.8), and several other bugs in netfilter, XFS, and the SMB client. For CVE-2025-21858, affected Linux kernel versions range from 4.2 to 6.13.5, with fixes available in versions 6.1.130, 6.6.80, 6.12.17, and 6.13.5. The update requires a system reboot and applies specifically to Red Hat Enterprise Linux 8.6 Advanced Mission Critical and Extended Update Support.
Red Hat Product Errata RHSA-2026:26570 - Security Advisory Issued: 2026-06-17 Updated: 2026-06-17 RHSA-2026:26570 - Security Advisory Overview Updated Packages Synopsis Important: kernel security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic 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. Description 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. 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 for x86_64 - Extended Update Support Extension 8.6 x86_64 Red Hat Enterprise Linux Server - AUS 8.6 x86_64 Fixes BZ - 2351619 - CVE-2025-21858 kernel: geneve: Fix use-after-free in geneve_find_dev(). BZ - 2429065 - CVE-2025-68800 kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats BZ - 2448594 - CVE-2026-23243 kernel: Linux kernel: Denial of service and memory corruption in RDMA umad BZ - 2451218 - CVE-2026-23392 kernel: netfilter: nf_tables: release flowtable after rcu grace period on error BZ - 2467005 - CVE-2026-43116 kernel: netfilter: ctnetlink: ensure safe access to master conntrack BZ - 2467210 - CVE-2026-43158 kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks BZ - 2481486 - CVE-2026-46243 kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions CVEs CVE-2025-21858 CVE-2025-68800 CVE-2026-23243 CVE-2026-23392 CVE-2026-43116 CVE-2026-43158 CVE-2026-46243 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. 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