Detections
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Amazon Linux 2023 : libvirt, libvirt-client, libvirt-client-qemu (ALAS2023-2026-2139)

high Nessus Plugin ID 345790

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-2139 advisory.

 A flaw was found in libvirt. An unprivileged local user could exploit an integer overflow vulnerability in the NodeGetFreePages RPC handler. This flaw allows crafted values to bypass a size check, leading to an undersized memory buffer. Subsequently, real NUMA node data can overwrite this buffer. This heap buffer overflow can corrupt the root libvirt daemon's memory, potentially leading to a denial of service or local privilege escalation. (CVE-2026-18917)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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

Solution

Run 'dnf update libvirt --releasever 2023.12.20260914' or or 'dnf update --advisory ALAS2023-2026-2139 --releasever 2023.12.20260914' to update your system.

See Also

https://alas.aws.amazon.com//AL2023/ALAS2023-2026-2139.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-18917.html

Plugin Details

Severity: High

ID: 345790

File Name: al2023_ALAS2023-2026-2139.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/14/2026

Updated: 9/14/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.19

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-2026-18917

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: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:libvirt-client-debuginfo, p-cpe:/a:amazon:linux:libvirt-client-qemu, p-cpe:/a:amazon:linux:libvirt-client, p-cpe:/a:amazon:linux:libvirt-daemon-common-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-common, p-cpe:/a:amazon:linux:libvirt-daemon-config-network, p-cpe:/a:amazon:linux:libvirt-daemon-config-nwfilter, p-cpe:/a:amazon:linux:libvirt-daemon-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-interface-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-interface, p-cpe:/a:amazon:linux:libvirt-daemon-driver-network-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-network, p-cpe:/a:amazon:linux:libvirt-daemon-driver-nodedev-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-nodedev, p-cpe:/a:amazon:linux:libvirt-daemon-driver-nwfilter-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-nwfilter, p-cpe:/a:amazon:linux:libvirt-daemon-driver-qemu-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-qemu, p-cpe:/a:amazon:linux:libvirt-daemon-driver-secret-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-secret, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-core-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-core, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-disk-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-disk, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-logical-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage-logical, p-cpe:/a:amazon:linux:libvirt-daemon-driver-storage, p-cpe:/a:amazon:linux:libvirt-daemon-kvm, p-cpe:/a:amazon:linux:libvirt-daemon-lock-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-lock, p-cpe:/a:amazon:linux:libvirt-daemon-log-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-log, p-cpe:/a:amazon:linux:libvirt-daemon-plugin-lockd-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-plugin-lockd, p-cpe:/a:amazon:linux:libvirt-daemon-proxy-debuginfo, p-cpe:/a:amazon:linux:libvirt-daemon-proxy, p-cpe:/a:amazon:linux:libvirt-daemon-qemu, p-cpe:/a:amazon:linux:libvirt-daemon, p-cpe:/a:amazon:linux:libvirt-debuginfo, p-cpe:/a:amazon:linux:libvirt-debugsource, p-cpe:/a:amazon:linux:libvirt-devel, p-cpe:/a:amazon:linux:libvirt-docs, p-cpe:/a:amazon:linux:libvirt-libs-debuginfo, p-cpe:/a:amazon:linux:libvirt-libs, p-cpe:/a:amazon:linux:libvirt-nss-debuginfo, p-cpe:/a:amazon:linux:libvirt-nss, p-cpe:/a:amazon:linux:libvirt-ssh-proxy-debuginfo, p-cpe:/a:amazon:linux:libvirt-ssh-proxy, p-cpe:/a:amazon:linux:libvirt

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

Exploit Ease: No known exploits are available

Patch Publication Date: 9/14/2026

Vulnerability Publication Date: 8/20/2026

Reference Information

CVE: CVE-2026-18917