CVE-2026-34481

high Apache
CVSS v3 Base Score
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score
0.2%
Exploitation probability in 30 days
Top 64% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
High
Availability
None
Published: April 10, 2026 (33 days ago)
Last Modified: April 24, 2026
Vendor: Apache
Source: NVD

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.

CWE

CWE-116

Affected Products

apache log4j

References

🔗 github.com 🔗 lists.apache.org 🔗 logging.apache.org 🔗 logging.apache.org 🔗 logging.apache.org