RHSA-2026:21706 — 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 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: 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.