RHSA-2026:25121 — Security Advisory

An update for kernel is now available for Red Hat Enterprise Linux 8.

Red Hat Product Security has rated this update as having a security impact of Critical. 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: smc: Fix use-after-free in tcp_write_timer_handler() (CVE-2023-53781)

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

• kernel: libceph: prevent potential out-of-bounds reads in handle_auth_done() (CVE-2026-22984)

• kernel: libceph: replace overzealous BUG_ON in osdmap_apply_incremental() (CVE-2026-22990)

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

• kernel: ALSA: 6fire: fix use-after-free on disconnect (CVE-2026-31581)

• kernel: smb: client: fix OOB reads parsing symlink error response (CVE-2026-31613)

• 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: dlm: validate length in dlm_search_rsb_tree (CVE-2026-43125)

• kernel: RDMA/rxe: Fix double free in rxe_srq_from_init (CVE-2026-45852)

• kernel: RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event() (CVE-2026-46181)

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.