A memory leak vulnerability (CVE-2026-64002, CVSS 7.8 HIGH) in the Linux kernel's IPv4 subsystem occurs when the `sysctl_local_reserved_ports` structure is not freed after unregistering a sysctl table. This security update for the kernel is rated Important and affects Red Hat Enterprise Linux 8.4 under specific support add-ons. The fix is applied via the updated kernel packages referenced in the advisory, and a system reboot is required for the update to take effect.
Red Hat Product Errata RHSA-2026:61959 - Security Advisory Issued: 2026-09-01 Updated: 2026-09-01 RHSA-2026:61959 - 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 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 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: ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table() (CVE-2026-64002) 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 x86_64 - Extended Life Cycle Long Life 8.4 x86_64 Red Hat Enterprise Linux Server - AUS 8.4 x86_64 Fixes BZ - 2502363 - CVE-2026-64002 kernel: ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table() CVEs CVE-2026-64002 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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More contact details at https://access.redhat.com/security/team/contact/ .