RHSA-2026:21745 — 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 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-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

• kernel: Bluetooth: MGMT: Fix possible UAFs (CVE-2025-39981)

• kernel: ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr (CVE-2025-68183)

• kernel: ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events (CVE-2025-68347)

• kernel: libceph: make decode_pool() more resilient against corrupted osdmaps (CVE-2025-71116)

• 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: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() (CVE-2026-23455)

• kernel: Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold (CVE-2026-31408)

• kernel: can: raw: fix ro->uniq use-after-free in raw_rcv() (CVE-2026-31532)

• kernel: net: sched: act_csum: validate nested VLAN headers (CVE-2026-31684)

• kernel: netfilter: ip6t_eui64: reject invalid MAC header for all packets (CVE-2026-31685)

• kernel: netfilter: nf_conntrack_helper: pass helper to expect cleanup (CVE-2026-43027)

• kernel: Bluetooth: MGMT: validate LTK enc_size on load (CVE-2026-43020)

• kernel: HID: wacom: fix out-of-bounds read in wacom_intuos_bt_irq (CVE-2026-43051)

• kernel: smb: client: validate the whole DACL before rewriting it in cifsacl (CVE-2026-31709)

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

• kernel: netfilter: xt_tcpmss: check remaining length before reading optlen (CVE-2026-43190)

• kernel: xfs: fix freemap adjustments when adding xattrs to leaf blocks (CVE-2026-43158)

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.