High severity7.5NVD Advisory· Published Apr 10, 2026· Updated Apr 24, 2026
CVE-2026-34481
CVE-2026-34481
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.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
org.apache.logging.log4j:log4j-layout-template-jsonMaven | >= 2.14.0, < 2.25.4 | 2.25.4 |
org.apache.logging.log4j:log4j-layout-template-jsonMaven | >= 3.0.0-alpha1, <= 3.0.0-beta3 | — |
Affected products
7cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*+ 6 more
- cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*range: >=2.14.0,<2.25.4
- cpe:2.3:a:apache:log4j:3.0.0:alpha1:*:*:*:*:*:*
- cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc1:*:*:*:*:*:*
- cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc2:*:*:*:*:*:*
- cpe:2.3:a:apache:log4j:3.0.0:beta1:*:*:*:*:*:*
- cpe:2.3:a:apache:log4j:3.0.0:beta2:*:*:*:*:*:*
- cpe:2.3:a:apache:log4j:3.0.0:beta3:*:*:*:*:*:*
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
8- www.openwall.com/lists/oss-security/2026/04/10/10nvdMailing ListThird Party AdvisoryWEB
- github.com/advisories/GHSA-w35j-pv5h-q9q9ghsaADVISORY
- lists.apache.org/thread/n34zdv00gbkdbzt2rx9rf5mqz6lhopcvnvdMailing ListVendor AdvisoryWEB
- logging.apache.org/security.htmlnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-34481ghsaADVISORY
- github.com/apache/logging-log4j2/pull/4080nvdIssue TrackingWEB
- logging.apache.org/cyclonedx/vdr.xmlnvdProductWEB
- logging.apache.org/log4j/2.x/manual/json-template-layout.htmlnvdTechnical DescriptionWEB
News mentions
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