RHEL 8 : kernel (RHSA-2026:26563)

high Nessus Plugin ID 321352

Synopsis

The remote Red Hat host is missing one or more security updates for kernel.

Description

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:26563 advisory.

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

* kernel: crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id (CVE-2025-68724)

* kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800)

* kernel: iommu: disable SVA when CONFIG_X86 is set (CVE-2025-71089)

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

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

* kernel: netfilter: ctnetlink: ensure safe access to master conntrack (CVE-2026-43116)

* kernel: wifi: brcmfmac: validate bsscfg indices in IF events (CVE-2026-43110)

* 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)

* kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243)

* kernel: sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL (CVE-2026-46227)

* kernel: wifi: mac80211: remove station if connection prep fails (CVE-2026-46125)

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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL kernel package based on the guidance in RHSA-2026:26563.

See Also

https://access.redhat.com/security/updates/classification/#important

https://bugzilla.redhat.com/show_bug.cgi?id=2351619

https://bugzilla.redhat.com/show_bug.cgi?id=2424881

https://bugzilla.redhat.com/show_bug.cgi?id=2424886

https://bugzilla.redhat.com/show_bug.cgi?id=2429065

https://bugzilla.redhat.com/show_bug.cgi?id=2429104

https://bugzilla.redhat.com/show_bug.cgi?id=2429602

https://bugzilla.redhat.com/show_bug.cgi?id=2432389

https://bugzilla.redhat.com/show_bug.cgi?id=2432400

https://bugzilla.redhat.com/show_bug.cgi?id=2451218

https://bugzilla.redhat.com/show_bug.cgi?id=2461759

https://bugzilla.redhat.com/show_bug.cgi?id=2467005

https://bugzilla.redhat.com/show_bug.cgi?id=2467014

https://bugzilla.redhat.com/show_bug.cgi?id=2467059

https://bugzilla.redhat.com/show_bug.cgi?id=2467064

https://bugzilla.redhat.com/show_bug.cgi?id=2467210

https://bugzilla.redhat.com/show_bug.cgi?id=2481486

https://bugzilla.redhat.com/show_bug.cgi?id=2482564

https://bugzilla.redhat.com/show_bug.cgi?id=2482608

http://www.nessus.org/u?48e7d0d2

https://access.redhat.com/errata/RHSA-2026:26563

Plugin Details

Severity: High

ID: 321352

File Name: redhat-RHSA-2026-26563.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/17/2026

Updated: 6/17/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2025-71089

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-core, cpe:/o:redhat:rhel_e4s:8.8, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, cpe:/o:redhat:rhel_tus:8.8

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/17/2026

Vulnerability Publication Date: 4/9/2024

Reference Information

CVE: CVE-2025-21858, CVE-2025-68366, CVE-2025-68724, CVE-2025-68800, CVE-2025-71089, CVE-2025-71116, CVE-2026-22984, CVE-2026-22990, CVE-2026-23392, CVE-2026-31685, CVE-2026-43110, CVE-2026-43116, CVE-2026-43158, CVE-2026-43163, CVE-2026-43190, CVE-2026-46125, CVE-2026-46227, CVE-2026-46243

CWE: 125, 1285, 1287, 190, 367, 416, 617, 820, 825, 911

RHSA: 2026:26563