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TI-2026-26739 Aliases CVE-2026-34481GHSA-w35j-pv5h-q9q9

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

Priority LOW 29CWE-116Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 6 fixed, 3 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00718 54th percentileScored 2026-11-07
Fix Partial Apache Log4j JSON Template Layout (Apache Software Foundation): 2.25.4org.apache.logging.log4j:log4j-layout-template-json (Maven): 2.25.4Red Hat: 6 advisoriesRed Hat: 6 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache Log4j JSON Template Layout2.14.0 to before 2.25.4; 3.0.0-alpha1 – 3.0.0-beta32.25.4Patch availableCNA
—org.apache.logging.log4j:log4j-layout-template-json (Maven)2.14.0 to before 2.25.42.25.4Patch availableGHSA-w35j-pv5h-q9q9
—org.apache.logging.log4j:log4j-layout-template-json (Maven)3.0.0-alpha1 – 3.0.0-beta3—No fix listedGHSA-w35j-pv5h-q9q9
  • Apache Log4j JSON Template Layout VendorApache Affected 2.14.0 to before 2.25.4; 3.0.0-alpha1 – 3.0.0-beta3 Fixed in 2.25.4 Patch available CNA
  • org.apache.logging.log4j:log4j-layout-template-json (Maven) Vendor— Affected 2.14.0 to before 2.25.4 Fixed in 2.25.4 Patch available GHSA-w35j-pv5h-q9q9
  • org.apache.logging.log4j:log4j-layout-template-json (Maven) Vendor— Affected 3.0.0-alpha1 – 3.0.0-beta3 Fixed in — No fix listed GHSA-w35j-pv5h-q9q9

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*2.14.0 to before 2.25.4VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:alpha1:*:*:*:*:*:*3.0.0 alpha1VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc1:*:*:*:*:*:*3.0.0 alpha1_rc1VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc2:*:*:*:*:*:*3.0.0 alpha1_rc2VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:beta1:*:*:*:*:*:*3.0.0 beta1VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:beta2:*:*:*:*:*:*3.0.0 beta2VulnerableApache
cpe:2.3:a:apache:log4j:3.0.0:beta3:*:*:*:*:*:*3.0.0 beta3VulnerableApache
  • cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* Versions 2.14.0 to before 2.25.4 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:alpha1:*:*:*:*:*:* Versions 3.0.0 alpha1 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc1:*:*:*:*:*:* Versions 3.0.0 alpha1_rc1 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc2:*:*:*:*:*:* Versions 3.0.0 alpha1_rc2 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:beta1:*:*:*:*:*:* Versions 3.0.0 beta1 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:beta2:*:*:*:*:*:* Versions 3.0.0 beta2 Vulnerable ·Apache
  • cpe:2.3:a:apache:log4j:3.0.0:beta3:*:*:*:*:*:* Versions 3.0.0 beta3 Vulnerable ·Apache

Remediation

  • Fix · CNA Apache Log4j JSON Template Layout (Apache Software Foundation) Fixed in 2.25.4
  • Fix · GHSA-w35j-pv5h-q9q9 org.apache.logging.log4j:log4j-layout-template-json (Maven) Fixed in 2.25.4 Advisory →

Red Hat 6 advisories

  • RHSA-2026:66545 Released 2026-09-10 · Red Hat rating Important
    Red Hat AMQ Broker 7.13.6 release and security update
    • Red Hat AMQ Broker 7.13.6
  • RHSA-2026:66488 Released 2026-09-10 · Red Hat rating Important
    Red Hat AMQ Broker 7.14.1 release and security update
    • Red Hat AMQ Broker 7.14.1
  • RHSA-2026:54435 Released 2026-08-12 · Red Hat rating Important
    Streams for Apache Kafka 3.2.1 release and security update
    • Streams for Apache Kafka 3.2.1
Show 3 more Red Hat advisories
  • RHSA-2026:37390 Released 2026-07-09 · Red Hat rating Important
    Red Hat Build of Apache Camel 4.18.1.P1 for Spring Boot release.
    • Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
  • RHSA-2026:22619 Released 2026-06-02 · Red Hat rating Important
    Red Hat Data Grid 8.6.1 security update
    • Red Hat Data Grid 8.6.1
  • RHSA-2026:21773 Released 2026-05-28 · Red Hat rating Important
    Red Hat Offline Knowledge Portal security and content update
    • Red Hat Offline Knowledge Portal 1.2.13 registry.redhat.io/offline-knowledge-portal/rhokp-rhel9

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Application Platform 7AffectedNo fix planned: Will not fix
Red Hat Offline Knowledge PortalAffectedNo fix yet
Red Hat AMQ Broker 7.13.6Fixed RHSA-2026:66545
Red Hat AMQ Broker 7.14.1Fixed RHSA-2026:66488
Red Hat Data Grid 8.6.1Fixed RHSA-2026:22619
Red Hat Offline Knowledge Portal 1.2.13Fixed RHSA-2026:21773
Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16Fixed RHSA-2026:37390
Streams for Apache Kafka 3.2.1Fixed RHSA-2026:54435
Not affected: 3 products
  • Red Hat Enterprise Linux 8
  • Red Hat JBoss Enterprise Application Platform 8
  • Red Hat JBoss Enterprise Application Platform Expansion Pack

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34481
  2. 2026-10-03 Alias added: GHSA-w35j-pv5h-q9q9
  3. 2026-10-10 Affected versions changed · Red Hat

References

Patch 1

Advisory 5

Other 2

  • TI-2021-19919 Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints KEVCVSS 3.1CRITICAL 10.0
  • TI-2021-20393 Apache Log4j2 Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack KEVCVSS 3.1CRITICAL 9.0
  • TI-2017-03645 Deserialization of untrusted data in Apache Log4j CVSS 3.1CRITICAL 9.8
  • TI-2019-13113 Deserialization of untrusted data in Apache Log4j CVSS 3.1CRITICAL 9.8
  • TI-2022-07428 SQL injection in JDBC Appender in Apache Log4j V1 CVSS 3.1CRITICAL 9.8
  • TI-2022-07425 Deserialization of untrusted data in JMSSink in Apache Log4j 1.x CVSS 3.1HIGH 8.8
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences