RHSA-2026:25120 — Security Advisory

An update for kernel-rt 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-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

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.