logging-log4j2 rel/2.25.4

This patch release delivers fixes for configuration inconsistencies and formatting issues across several layouts.

• Restores alignment between documented and actual configuration attributes.
• Fixes formatting and sanitization issues in XML and RFC5424 layouts.
• Improves handling of invalid characters and non-standard values.

The authoritative list of recognized configuration attributes is available in the PluginReference.

Fixed

• Don’t issue warnings if extra argument in parameterized logging is null. (#3975, #4014)
• Restore support for documented Rfc5424Layout parameter names. (#4022, #4074)
• Take Throwable#toString() into account while rendering stack traces in Pattern Layout. (#3623, #4033)
• Added debug level logs for successful resource loading in Loader class. (#4058, #4060)
• Align SslConfiguration factory method usage with Log4j 2.12+ API. The verifyHostname attribute is now correctly recognized. (#4061, #4075)
• Fix sanitization of structured data parameter names in RFC5424 layout. (#4073)
• Replace invalid characters in XmlLayout output with the Unicode replacement character (U+FFFD). (#4077)
• Replace invalid characters in Log4j1XmlLayout output with the Unicode replacement character (U+FFFD). (#4078)
• Replace invalid characters in MapMessage.asXml() output with the Unicode replacement character (U+FFFD). (#4079)
• Write non-finite floating-point numbers as strings in JsonWriter. (#4080)

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Source apache/logging-log4j2 · rel/2.25.4 · 2026-03-28 · upstream release

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