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AlmaLinux 9.6 [TuxCare] Security Update: log4j / log4j-jcl / log4j-slf4j / log4j-web (ALMALINUX9.6:CLSA-2026:1779124827)

medium Nessus Plugin ID 352053

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-2026:1779124827 advisory.

 - The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records. Two groups of users are affected: * Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file. * Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class. Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue. Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge. (CVE-2026-34479)

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-2026:1779124827.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1779124827

http://www.nessus.org/u?9c18b89f

Plugin Details

Severity: Medium

ID: 352053

File Name: tuxcare_alma_linux_9.6_CLSA-2026-1779124827.nasl

Version: 1.1

Type: Local

Published: 9/30/2026

Updated: 9/30/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.73

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

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

CVSS Score Source: CVE-2026-34479

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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

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

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 5.5

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/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 Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/18/2026

Vulnerability Publication Date: 4/10/2026

Reference Information

CVE: CVE-2026-34479

CLSA: 2026:1779124827