RHSA-2026:21209 — Security Advisory

An update for kernel is now available for Red Hat Enterprise Linux 9.4 Extended Update Support.

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: proc: fix UAF in proc_get_inode() (CVE-2025-21999)

• kernel: proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al (CVE-2025-38653)

• kernel: net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit (CVE-2025-39766)

• kernel: nbd: defer config unlock in nbd_genl_connect (CVE-2025-68366)

• kernel: scsi: qla2xxx: Fix improper freeing of purex item (CVE-2025-68741)

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

• kernel: Linux kernel: Use-after-free in traffic control (act_ct) may lead to denial of service or privilege escalation (CVE-2026-23270)

• kernel: Linux kernel: Use-after-free in bonding driver leads to denial of service (CVE-2026-31419)

• kernel: md/bitmap: fix GPF in write_page caused by resize race (CVE-2026-43163)

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.