Ubuntu 22.04 LTS / 24.04 LTS : libxml2 vulnerability (USN-8456-1)

high Nessus Plugin ID 322479

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-8456-1 advisory.

Geoffrey Humphreys discovered that libxml2 had a use after free when parsing the internal subset of a DTD.
A remote attacker could possibly use this issue to cause a denial of service or possibly execute arbitrary code.

Tenable has extracted the preceding description block directly from the Ubuntu 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

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8456-1

Plugin Details

Severity: High

ID: 322479

File Name: ubuntu_USN-8456-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/24/2026

Updated: 6/24/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2026-6653

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS v4

Risk Factor: High

Base Score: 8.3

Threat Score: 4.9

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:python3-libxml2, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libxml2-dev, p-cpe:/a:canonical:ubuntu_linux:libxml2-utils

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Ease: No known exploits are available

Patch Publication Date: 6/22/2026

Vulnerability Publication Date: 6/4/2026

Reference Information

CVE: CVE-2026-6653

IAVA: 2026-A-0532

USN: 8456-1