Invalid JSON output in Apache Log4j JsonTemplateLayout
Apache Log4j JsonTemplateLayout, in versions up to and including 2.25.3, improperly serializes non-finite floating-point values such as NaN, Infinity, and -Infinity when they appear in logged events. Because these values are not permitted by RFC 8259 JSON, the layout can emit invalid JSON records. The issue is exploitable only when an application is configured to use JsonTemplateLayout and logs a MapMessage containing an attacker-controlled floating-point value. The flaw affects log output generation rather than direct code execution, and can cause downstream systems that consume structured logs to reject or fail to index affected records.
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Cross-references every affected SKU, including bundled OEM variants.
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