Amazon Linux 2 : dnsmasq, --advisory ALAS2-2026-3318 (ALAS-2026-3318)

high Nessus Plugin ID 317029

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of dnsmasq installed on the remote host is prior to 2.76-16. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3318 advisory.

A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq allows local attackers to execute arbitrary code with root privileges via a crafted DHCPv6 packet. (CVE-2026-4892)

An information disclosure vulnerability in dnsmasq allows remote attackers to bypass source checks via a crafted DNS packet with RFC 7871 client subnet information. (CVE-2026-4893)

Tenable has extracted the preceding description block directly from the tested product 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

Run 'yum update dnsmasq' or or 'yum update --advisory ALAS2-2026-3318' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-3318.html

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

https://explore.alas.aws.amazon.com/CVE-2026-4892.html

https://explore.alas.aws.amazon.com/CVE-2026-4893.html

Plugin Details

Severity: High

ID: 317029

File Name: al2_ALAS-2026-3318.nasl

Version: 1.2

Type: Local

Agent: unix

Published: 5/27/2026

Updated: 6/2/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 8.3

Temporal Score: 6.5

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

CVSS Score Source: CVE-2026-4892

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.6

Vector: CVSS:3.0/AV:L/AC:L/PR:N/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:amazon:linux:dnsmasq, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:dnsmasq-debuginfo, p-cpe:/a:amazon:linux:dnsmasq-utils

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 5/11/2026

Reference Information

CVE: CVE-2026-4892, CVE-2026-4893

IAVA: 2026-A-0450