Amazon Linux 2 : libxml2, --advisory ALAS2-2026-3827 (ALAS-2026-3827)

low Nessus Plugin ID 332010

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 a vulnerability as referenced in the ALAS2-2026-3827 advisory.

libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in
--shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking.By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame.Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process.

This issue has been fixed in the commit c2e233fc.

NOTE:The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug. (CVE-2026-11979)

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 libxml2' or or 'yum update --advisory ALAS2-2026-3827' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-3827.html

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

https://explore.alas.aws.amazon.com/CVE-2026-11979.html

Plugin Details

Severity: Low

ID: 332010

File Name: al2_ALAS-2026-3827.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 8/4/2026

Updated: 8/4/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.44

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-11979

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

CVSS v4

Risk Factor: Low

Base Score: 1.8

Threat Score: 0.2

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:L/SI:L/SA:N

Vulnerability Information

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

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/4/2026

Vulnerability Publication Date: 6/29/2026

Reference Information

CVE: CVE-2026-11979