Advisories for Maven/Org.apache.logging.log4j/Log4j-Layout-Template-Json package

2026

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

Apache Log4j's JsonTemplateLayout, 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 …