CVE-2026-49844

Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: wh...

CVE-2026-49844: Improper Encoding or Escaping of Output

Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: wh...

org.apache.logging.log4j/log4j-core: Apache Log4j Core: Invalid XML output causes denial of service in logging

A flaw was found in Apache Log4j Core. The XmlLayout component, responsible for formatting log messages into XML, does not properly remove or replace characters that are not allowed in XML 1.0. When log messages or diagnostic information contain these forbidden characters, the resulting XML outpu...

Security Bulletin: The Apache Log4J 2 package that is shipped with IBM ApplinX is vulnerable to multiple vulnerabilities (CVE-2026-34480, CVE-2026-34477, CVE-2026-34478, CVE-2026-34479).

Summary The Apache Log4J 2 package that is shipped with IBM ApplinX is vulnerable to an Improper Encoding or Escaping of Output vulnerability, an Improper Validation of Certificate with Host Mismatch vulnerability and an Improper Output Neutralization for Logs vulnerability CVE-2026-34480,...

org.apache.logging.log4j/log4j-core: Apache Log4j Core: Log injection via CRLF sequences due to configuration attribute renames

A flaw was found in Apache Log4j Core. This vulnerability allows for log injection through the use of Carriage Return Line Feed CRLF sequences. This occurs because security-related configuration attributes were silently renamed, impacting users who directly configure Rfc5424Layout with stream-bas...

org.apache.logging.log4j/log4j-core: Apache Log4j Core: Invalid XML output causes denial of service in logging

A flaw was found in Apache Log4j Core. The XmlLayout component, responsible for formatting log messages into XML, does not properly remove or replace characters that are not allowed in XML 1.0. When log messages or diagnostic information contain these forbidden characters, the resulting XML outpu...

Security Bulletin: IBM App Connect for Manufacturing is vulnerable to multiple vulnerabilities due to Apache Log4j and Bouncy Castle.

Summary IBM App Connect for Manufacturing is vulnerable to multiple vulnerabilities due to Apache Log4j and Bouncy Castle. Vulnerability Details CVEID:CVE-2026-34477 DESCRIPTION: The fix for CVE-2025-68161 https://logging.apache.org/security.htmlCVE-2025-68161 was incomplete: it addressed hostnam...

Apache Log4j 2.12.0 < 2.25.4 SSL Hostname Verification Bypass (CVE-2026-34477)

The version of Apache Log4j on the remote host is 2.12.0 through 2.25.3. It is, therefore, affected by a vulnerability: - The verifyHostName configuration attribute of the Ssl element was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception via...

Improper Certificate Validation

Apache Log4j Core is vulnerable to Improper Certificate Validation. The vulnerability is due to ignored hostname verification settings in TLS configuration, which allows an attacker to perform a man-in-the-middle attack by presenting a trusted certificate and intercepting secure communications...

CVE-2026-34480

A flaw was found in Apache Log4j Core. The XmlLayout component, responsible for formatting log messages into XML, does not properly remove or replace characters that are not allowed in XML 1.0. When log messages or diagnostic information contain these forbidden characters, the resulting XML outpu...

Linux Distros Unpatched Vulnerability : CVE-2026-34481

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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 inval...

Improper Output Handling

Apache Log4j is vulnerable to Improper Output Handling. The vulnerability is due to JsonTemplateLayout generating invalid JSON when processing non-finite floating-point values e.g., NaN, Infinity, which are not compliant with RFC 8259, allowing attacker-controlled data in log events to produce...

EUVD-2026-21412

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. Th...

GHSA-445C-VH5M-36RJ Apache Log4j Core: log injection in `Rfc5424Layout` due to silent configuration incompatibility

Apache Log4j Core's Rfc5424Layout, in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes. Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:...

CVE-2026-34481

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. Th...

CVE-2026-34481

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. Th...

CVE-2026-34480

Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.htmlXmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/charsets producing invalid XML output whenever a log message or M...

CVE-2026-34479

The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log...

Apache Log4j security vulnerability

Apache Log4j is an open-source logging tool based on Java, developed by the Apache Foundation in the United States. Versions of Apache Log4j Core 2.25.3 and earlier contain security vulnerabilities. These vulnerabilities stem from the silent ignoring of the verifyHostName configuration property,...

CVE-2026-34480: Improper Encoding or Escaping of Output

Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.htmlXmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/charsets producing invalid XML output whenever a log message or M...