Описание
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, or logs an object directly (e.g., via Logger.info(Object), which wraps it in an ObjectMessage), where the message contains an attacker-controlled floating-point value.
Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue.
Note: The fix released in version 2.25.4 did not cover all affected code paths. CVE-2026-49844 was assigned to the remaining issue, which concerns the MapMessage.asJson() serialization in Apache Log4j API and is fixed in versions 2.25.5 and 2.26.1.
A flaw was found in Apache Log4j's JsonTemplateLayout. This vulnerability allows a remote attacker to disrupt log processing systems. By sending log events that include specific non-numeric floating-point values, the attacker can cause the JsonTemplateLayout to generate invalid JSON output. This invalid output can then lead to downstream systems rejecting or failing to index these logs, effectively causing a denial of service for log analysis.
Отчет
Exploitation of this flaw requires an application to be configured with JsonTemplateLayout and to log attacker-controlled non-finite floating-point values within a MapMessage, which is not a default or common configuration in Red Hat products.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat AMQ Broker 7 | log4j-layout-template-json | Affected | ||
| Red Hat Enterprise Linux 8 | log4j:2/log4j | Affected | ||
| Red Hat Enterprise Linux 9 | log4j | Will not fix | ||
| Red Hat JBoss Enterprise Application Platform 7 | log4j-layout-template-json | Not affected | ||
| Red Hat JBoss Enterprise Application Platform 8 | log4j-layout-template-json | Not affected | ||
| Red Hat JBoss Enterprise Application Platform Expansion Pack | log4j-layout-template-json | Not affected | ||
| streams for Apache Kafka 3 | log4j-layout-template-json | Affected | ||
| Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 | log4j-layout-template-json | Fixed | RHSA-2026:37390 | 09.07.2026 |
| Red Hat Data Grid 8.6.1 | log4j-layout-template-json | Fixed | RHSA-2026:22619 | 02.06.2026 |
| Red Hat Offline Knowledge Portal 1.2.9 | offline-knowledge-portal/rhokp-rhel9 | Fixed | RHSA-2026:21773 | 28.05.2026 |
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Ссылки на источники
Дополнительная информация
Статус:
EPSS
6.5 Medium
CVSS3
Связанные уязвимости
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, or logs an object directly (e.g., via Logger.info(Object), which wraps it in an ObjectMessage), where the message contains an attacker-controlled floating-point value. Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue. Note: The fix released in version 2.25.4 did not cover all affected code paths. CVE-2026-49844 was assigned to the remaining issue, which concerns the MapMessage.asJson(...
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, or logs an object directly (e.g., via Logger.info(Object), which wraps it in an ObjectMessage), where the message contains an attacker-controlled floating-point value. Users are advised to upgrade to Apache Log4j JSON Template Layout 2.25.4, which corrects this issue. Note: The fix released in version 2.25.4 did not cover all affected code paths. CVE-2026-49844 was assigned to the remaining issue, which concerns the MapMessage.a
Apache Log4j JSON Template Layout: Improper serialization of non-finite floating-point values in JsonTemplateLayout
Apache Log4j's JsonTemplateLayout https://logging.apache.org/log4j/2. ...
Apache Log4j JSON Template Layout: Improper serialization of non-finite floating-point values in JsonTemplateLayout
EPSS
6.5 Medium
CVSS3