CVE 6.3 MEDIUM

Apache Log4j JSON Template Layout: Improper serialization of non-finite floating-point values in JsonTemplateLayout_CVE-2026-34481

6.3 / 10
MEDIUM
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

Description

Apache Log4j's JsonTemplateLayout https://logging.apache.org/log4j/2.x/manual/json-template-layout.html , in versions up to and including 2.25.3, produces invalid JSON output when log events contain non-finite floating-point values (NaN, Infinity, or -Infinity), which are prohibited by RFC 8259. This may cause downstream log processing systems to reject or fail to index affected records.

An attacker can exploit this issue only if both of the following conditions are met:

* The application uses JsonTemplateLayout.
* The application logs a MapMessage containing an attacker-controlled floating-point value.


Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue.

Basic Information

ID CVE-2026-34481
Source apache
Published Apr 10, 2026 at 15:43
Modified Apr 10, 2026 at 17:41

Affected Product

Vendor Apache Software Foundation
Product Apache Log4j JSON Template Layout
Version 2.14.0
Affected Versions Apache Software Foundation Apache Log4j JSON Template Layout 2.14.0
Apache Software Foundation Apache Log4j JSON Template Layout 3.0.0-alpha1

CWE Classification

References

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