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CVE-2026-34477

Estado: AnalizadaMedia (6.3)—

The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the <Ssl> element.

Although the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.

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A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:

Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.

Detalles técnicos trazas, registros y código del informe original
  *  An SMTP, Socket, or Syslog appender is in use.
  *  TLS is configured via a nested <Ssl> element.
  *  The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured.
This issue does not affect users of the HTTP appender, which uses a separate  verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName  attribute that was not subject to this bug and verifies host names by default.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Apache — Log4j

CWE

Referencias

JSON original (NVD)

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