RHEL 8 : kernel (RHSA-2026:26570)

high Nessus Plugin ID 321486

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-2026:26570 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: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800)

* kernel: Linux kernel: Denial of service and memory corruption in RDMA umad (CVE-2026-23243)

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

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

* 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)

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-2026:26570.

Plugin Details

Severity: High

ID: 321486

File Name: redhat-RHSA-2026-26570.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 6/18/2026

Updated: 6/18/2026

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-2025-21858

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-modules-extra, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, cpe:/o:redhat:rhel_aus:8.6, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:perf

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-2025-68800, CVE-2026-23243, CVE-2026-23392, CVE-2026-43116, CVE-2026-43158, CVE-2026-46243

CWE: 131, 416, 617, 825

RHSA: 2026:26570

Detections

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