๐Ÿ” CVE Alert

CVE-2026-34481

UNKNOWN 0.0

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

CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-116
Vendor apache software foundation
Product apache log4j json template layout
Published Apr 10, 2026
Last Updated Apr 10, 2026
Stay Ahead of the Next One

Get instant alerts for apache software foundation apache log4j json template layout

Be the first to know when new unknown vulnerabilities affecting apache software foundation apache log4j json template layout are published โ€” delivered to Slack, Telegram or Discord.

Get Free Alerts โ†’ Free ยท No credit card ยท 60 sec setup

Affected Versions

Apache Software Foundation / Apache Log4j JSON Template Layout
2.14.0 < 2.25.4 3.0.0-alpha1 โ‰ค 3.0.0-beta3

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/apache/logging-log4j2/pull/4080 logging.apache.org: https://logging.apache.org/security.html#CVE-2026-34481 logging.apache.org: https://logging.apache.org/cyclonedx/vdr.xml logging.apache.org: https://logging.apache.org/log4j/2.x/manual/json-template-layout.html lists.apache.org: https://lists.apache.org/thread/n34zdv00gbkdbzt2rx9rf5mqz6lhopcv openwall.com: http://www.openwall.com/lists/oss-security/2026/04/10/10

Credits

Ap4sh (Samy Medjahed) and Ethicxz (Eliott Laurie)