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-2026-34477

The fix for CVE-2025-68161 https://logging.apache.org/security.htmlCVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.htmllog4j2.sslVerifyHostName system property, but no...

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...

UBUNTU-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...

UBUNTU-CVE-2026-34477

The fix for CVE-2025-68161 https://logging.apache.org/security.htmlCVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.htmllog4j2.sslVerifyHostName system property, but no...

UBUNTU-CVE-2026-34478

Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.htmlRFC5424Layout , 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 user...

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

CVE-2026-34481 affects Apache Log4j’s JsonTemplateLayout. Versions up to 2.25.3 produce invalid JSON when log events contain non-finite floating-point values (NaN, Infinity, -Infinity), violating RFC 8259 and potentially causing downstream log processors to reject or fail indexing. Exploitation r...

CVE-2026-34481 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.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 JSON Template Layout: Improper serialization of non-finite floating-point values in JsonTemplateLayout

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

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: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

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-2026-34480 Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

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-2026-34480

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-2026-34480

Technical details about CVE-2026-34480 are not publicly available in the provided connected documents. The initial description gives an overview but no vendor/product/version specifics or remediation steps here. Monitor for updates from official advisories.

CVE-2026-34480 Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

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-2026-34478

Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.htmlRFC5424Layout , 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 user...

CVE-2026-34478 Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility

Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.htmlRFC5424Layout , 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 user...

CVE-2026-34478 Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility

Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.htmlRFC5424Layout , 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 user...

CVE-2026-34478

CVE-2026-34478 (Log4j Core) affects Apache Log4j Core 2.21.0 through 2.25.3 and involves CRLF log-injection risks in stream-based syslog output due to undocumented renames of configuration attributes in Rfc5424Layout. Specifically, the newLineEscape attribute was silently renamed, breaking newlin...