Improper Encoding or Escaping of Output Affecting org.apache.logging.log4j:log4j-layout-template-json package, versions [2.14.0, 2.25.4)[3.0.0-alpha1,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGAPACHELOGGINGLOG4J-15967756
- published10 Apr 2026
- disclosed10 Apr 2026
- creditSamy Medjahed, Eliott Laurie
Introduced: 10 Apr 2026
CVE-2026-34481 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output when JsonTemplateLayout logs a MapMessage. An attacker can cause downstream log processing systems to reject or fail to index affected records by supplying non-finite floating-point values (such as NaN, Infinity, or -Infinity) in a MapMessage.