RHEL 8 : kernel (RHSA-2026:59091)

high Nessus Plugin ID 339135

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-2026:59091 advisory.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

* kernel: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O (CVE-2025-40026)

* kernel: dlm: validate length in dlm_search_rsb_tree (CVE-2026-43125)

* kernel: xen: AMD Zen 2 Processors: Privilege escalation via improper CPU cache isolation (CVE-2025-54518)

* kernel: selinux: fix overlayfs mmap() and mprotect() access checks (CVE-2026-46054)

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-2026:59091.

Plugin Details

Severity: High

ID: 339135

File Name: redhat-RHSA-2026-59091.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/24/2026

Updated: 8/24/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.81

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-43125

CVSS v3

Risk Factor: High

Base Score: 7.9

Temporal Score: 6.9

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

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

CVSS Score Source: CVE-2025-40026

CVSS v4

Risk Factor: High

Base Score: 7.3

Threat Score: 4.4

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2025-54518

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:rhel_aus:8.4, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:python3-perf

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/24/2026

Vulnerability Publication Date: 10/23/2025

Reference Information

CVE: CVE-2025-40026, CVE-2025-54518, CVE-2026-43125, CVE-2026-46054

CWE: 1220, 130, 280, 754

RHSA: 2026:59091

Detections

Analytics