Rocky Linux 9.6 [TuxCare] Security Update: log4j / log4j-jcl / log4j-slf4j / log4j-web (ALMALINUX9.6:CLSA-2026:1784624635)

medium Nessus Plugin ID 360099

Synopsis

The Rocky Linux host is missing one or more security updates.

Description

The Rocky Linux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1784624635 advisory.

- Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the resulting document. The defect is reachable only when both of the following conditions hold: * The application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template- layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non- finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

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-2026:1784624635.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1784624635

http://www.nessus.org/u?7169af1a

Plugin Details

Severity: Medium

ID: 360099

File Name: tuxcare_rocky_linux_9.6_CLSA-2026-1784624635.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: Low

Score: 3

Percentile: 23.6

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4

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

CVSS Score Source: CVE-2026-49844

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:H/A:N

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

CVSS v4

Risk Factor: Medium

Base Score: 6.3

Threat Score: 1.7

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/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/RockyLinux/release, Host/RockyLinux/rpm-list, Host/OS/extended-third-party

Exploit Ease: No known exploits are available

Patch Publication Date: 7/21/2026

Vulnerability Publication Date: 7/10/2026

Reference Information

CVE: CVE-2026-49844

CLSA: 2026:1784624635