Amazon Linux 2 : libxml2, --advisory ALAS2-2026-3144 (ALAS-2026-3144)

medium Nessus Plugin ID 298135

Synopsis

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

Description

The version of libxml2 installed on the remote host is prior to 2.9.1-6. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3144 advisory.

A flaw was found in libxml2, an XML parsing library. This uncontrolled recursion vulnerability occurs in the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references itself. A remote attacker could exploit this configuration-dependent issue by providing a specially crafted XML catalog, leading to infinite recursion and call stack exhaustion. This ultimately results in a segmentation fault, causing a Denial of Service (DoS) by crashing affected applications. (CVE-2026-0990)

A flaw was found in the libxml2 library. This uncontrolled resource consumption vulnerability occurs when processing XML catalogs that contain repeated <nextCatalog> elements pointing to the same downstream catalog. A remote attacker can exploit this by supplying crafted catalogs, causing the parser to redundantly traverse catalog chains. This leads to excessive CPU consumption and degrades application availability, resulting in a denial-of-service condition. (CVE-2026-0992)

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 libxml2' or or 'yum update --advisory ALAS2-2026-3144' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-3144.html

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

https://explore.alas.aws.amazon.com/CVE-2026-0990.html

https://explore.alas.aws.amazon.com/CVE-2026-0992.html

Plugin Details

Severity: Medium

ID: 298135

File Name: al2_ALAS-2026-3144.nasl

Version: 1.1

Type: local

Agent: unix

Published: 2/5/2026

Updated: 2/5/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4

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

CVSS Score Source: CVE-2026-0990

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libxml2-devel, p-cpe:/a:amazon:linux:libxml2-debuginfo, p-cpe:/a:amazon:linux:libxml2, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:libxml2-python, p-cpe:/a:amazon:linux:libxml2-static

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

Exploit Ease: No known exploits are available

Patch Publication Date: 2/5/2026

Vulnerability Publication Date: 11/13/2025

Reference Information

CVE: CVE-2026-0990, CVE-2026-0992

IAVA: 2025-A-0840