RHEL 9 : kernel (RHSA-2026:9836)

high Nessus Plugin ID 309661

Synopsis

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

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:9836 advisory.

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

Security Fix(es):

* kernel: macvlan: fix possible UAF in macvlan_forward_source() (CVE-2026-23001)

* kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204)

* kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231)

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-2026:9836.

Plugin Details

Severity: High

ID: 309661

File Name: redhat-RHSA-2026-9836.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 4/22/2026

Updated: 4/22/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-23231

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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:U/RL:O/RC:C

Vulnerability Information

CPE: 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-core, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-core, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, cpe:/o:redhat:rhel_e4s:9.0, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:python3-perf, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-devel-matched

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: 4/22/2026

Vulnerability Publication Date: 1/25/2026

Reference Information

CVE: CVE-2026-23001, CVE-2026-23204, CVE-2026-23231

CWE: 1285, 416

RHSA: 2026:9836

Detections

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