AlmaLinux 9.6 [TuxCare] Security Update: libxml2 / libxml2-devel / libxml2-static / python3-libxml2 (ALMALINUX9.6:CLSA-2026:1783948495)

low Nessus Plugin ID 359951

Synopsis

The AlmaLinux host is missing one or more security updates.

Description

The AlmaLinux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1783948495 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)

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 based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1783948495.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1783948495

http://www.nessus.org/u?27bc4262

Plugin Details

Severity: Low

ID: 359951

File Name: tuxcare_alma_linux_9.6_CLSA-2026-1783948495.nasl

Version: 1.1

Type: Local

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.44

Vendor

Vendor Severity: Important

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

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/AlmaLinux/release, Host/AlmaLinux/rpm-list, Host/OS/extended-third-party

Exploit Ease: No known exploits are available

Patch Publication Date: 7/13/2026

Vulnerability Publication Date: 6/4/2026

Reference Information

CVE: CVE-2026-11979

CLSA: 2026:1783948495