CVE-2018-1285

CVE-2018-1285 affects Apache log4net up to version 2.0.9 (pre-2.0.10), where XML External Entity (XXE) processing is not disabled when parsing log4net configuration files, enabling XXE-based attacks in apps that accept attacker-controlled config. The connected IBM security bulletin confirms the v...

CVE-2026-40021

Apache Log4net before version 3.3.0 contains a vulnerability in XmlLayout and XmlLayoutSchemaLog4J where characters forbidden by XML 1.0 are not sanitized in MDC keys/values and the identity field. The issue causes a serialization exception and silent loss of the affected log event, which can be ...

CVE-2006-0743

CVE-2006-0743 affects Apache log4net 1.2.9 (LocalSyslogAppender) with a format string vulnerability that could cause a denial of service via memory corruption. The connected documents confirm the vulnerability in log4net 1.2.9 and describe DoS outcomes; some advisories note remediation by upgradi...

CVE-2026-105244

The Apache log4net logging framework (versions 1.2.12 before 3.5.0 ) contains an Improper Encoding or Escaping of Output vulnerability in the RemoteSyslogAppender component. Instead of escaping non-ASCII characters and control characters (like tabs), the appender silently deletes them. This allow...

CVE-2026-105239

The Apache log4net library (versions 1.2.9 through 3.5.0) is vulnerable to an Improper Neutralization of Null Byte or NUL Character in the EventLogAppender . When a NUL character is present in logged content, it prematurely terminates the Windows Event Log record, causing subsequent data—such as ...

CVE-2026-105243

The Apache log4net logging framework (versions 1.2.9 before 3.5.0 ) contains an Insufficient Logging vulnerability in the EventLogAppender component on Windows. The root cause is that long messages are truncated to a fixed size that exceeds the Windows Event Log capacity once log and source names...

CVE-2026-105242

The Apache log4net logging framework (versions 1.2.11 through 3.5.0 ) is vulnerable to an Improper Handling of Exceptional Conditions (CWE-755) in the aspnet-request pattern converter. When reading request parameters, certain content—such as markup—triggers ASP.NET request validation , causing th...

CVE-2026-105240

The Apache log4net logging framework (versions 1.2.9 before 3.5.0) is vulnerable to an Improper Neutralization of Null Byte or NUL Character (CWE-158) within the OutputDebugStringAppender . On Windows systems, a NUL character in logged content causes the debug output record to truncate prematurel...

CVE-2026-105241

The Apache log4net logging framework (versions 1.2.9 before 3.5.0 ) is vulnerable to an Improper Handling of Unicode Encoding issue within the SmtpPickupDirAppender component. If the mail file writer encounters content it cannot encode, such as an unpaired UTF-16 surrogate , it causes the write o...