Detections
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Unity Linux 20.1070e Security Update: log4j (UTSA-2026-099531)
medium Nessus Plugin ID 336926
Synopsis
The Unity Linux host is missing one or more security updates.Description
The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-099531 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.
Tenable has extracted the preceding description block directly from the Unity Linux 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 log4j package.See Also
https://atomgit.com/src-openeuler/log4j/issues/78
Plugin Details
Severity: Medium
ID: 336926
File Name: unity_linux_UTSA-2026-099531.nasl
Version: 1.1
Type: Local
Published: 8/17/2026
Updated: 8/17/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3
Percentile: 23.72
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/UOS-Server/release, Host/UOS-Server/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 8/10/2026
Vulnerability Publication Date: 7/10/2026
Reference Information
CVE: CVE-2026-49844