Amazon Linux 2 : expat, --advisory ALAS2-2026-3170 (ALAS-2026-3170)

medium Nessus Plugin ID 299537

Synopsis

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

Description

The version of expat installed on the remote host is prior to 2.1.0-15. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3170 advisory.

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation. (CVE-2026-25210)

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 'yum update expat' or or 'yum update --advisory ALAS2-2026-3170' to update your system.

Plugin Details

Severity: Medium

ID: 299537

File Name: al2_ALAS-2026-3170.nasl

Version: 1.1

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 2/19/2026

Updated: 2/19/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-25210

CVSS v3

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 6

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:expat-static, p-cpe:/a:amazon:linux:expat-debuginfo, p-cpe:/a:amazon:linux:expat-devel, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:expat

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

Exploit Ease: No known exploits are available

Patch Publication Date: 2/19/2026

Vulnerability Publication Date: 1/30/2026

Reference Information

CVE: CVE-2026-25210

IAVA: 2026-A-0100

Detections

Analytics