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log4net

Open actionable advisories and recorded vendor fixes. This public package view has no inventory attached and cannot establish whether your deployment is affected. A vendor fix never resolves your finding; verify your installed version and the source guidance.

Open advisories

3 actionable advisories, newest first. Withdrawn advisories and news are excluded. Coverage is partial.

  1. Medium, CVSS 6.3NuGetPublished

    Apache Log4net: Silent log event loss in XmlLayout and XmlLayoutSchemaLog4J due to unescaped XML 1.0 forbidden characters

    CVE-2026-40021 · GHSA-4f7c-pmjv-c25w

    Affected
    • NuGet log4net < 3.3.0
    Fixed in
    3.3.0· Vendor fix available
    Issue
    Apache Log4net's XmlLayout https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list and XmlLayoutSchemaLog4J https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list , in versions before 3.3.0, fail to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in MDC property keys and values, as well as the identity field that may carry attacker-influenced data. This causes an exception during serialization and the silent loss of the affected log event. An attacker who can influence any of these fields can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity. Users are advised to upgrade to Apache Log4net 3.3.0, which fixes this issue.

    Recommended action: Upgrade to 3.3.0 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →
  2. UnratedNuGetPublished

    Apache log4net format string vulnerability causes DoS

    CVE-2006-0743 · GHSA-f9fr-w54q-772h

    Affected
    • NuGet log4net <= 1.2.9
    Fixed in
    1.2.10· Vendor fix available
    Issue
    Format string vulnerability in LocalSyslogAppender in Apache log4net 1.2.9 might allow remote attackers to cause a denial of service (memory corruption and termination) via unknown vectors.

    Recommended action: Upgrade to 1.2.10 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →
  3. Critical, CVSS 9.8NuGetPublished

    XML External Entity attack in log4net

    CVE-2018-1285 · GHSA-2cwj-8chv-9pp9

    Affected
    • NuGet log4net < 2.0.10
    Fixed in
    2.0.10· Vendor fix available
    Issue
    Apache log4net before 2.0.10 does not disable XML external entities when parsing log4net configuration files. This could allow for XXE-based attacks in applications that accept arbitrary configuration files from users.

    Recommended action: Upgrade to 2.0.10 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.

    Sources:github.comSource checked Evidence →