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.
A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:
* 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.
Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Fri, 10 Apr 2026 18:15:00 +0000
| Type | Values Removed | Values Added |
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| Metrics |
ssvc
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Fri, 10 Apr 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
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| Description | 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. A network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met: * 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. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue. | |
| Title | Apache Log4j Core: verifyHostName attribute silently ignored in TLS configuration, allowing hostname verification bypass | |
| First Time appeared |
Apache
Apache log4j |
|
| Weaknesses | CWE-297 | |
| CPEs | cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Apache
Apache log4j |
|
| References |
|
|
| Metrics |
cvssV4_0
|
Projects
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Status: PUBLISHED
Assigner: apache
Published:
Updated: 2026-04-10T17:38:57.154Z
Reserved: 2026-03-28T11:26:04.052Z
Link: CVE-2026-34477
Updated: 2026-04-10T17:38:37.230Z
Status : Received
Published: 2026-04-10T16:16:30.843
Modified: 2026-04-10T16:16:30.843
Link: CVE-2026-34477
No data.
OpenCVE Enrichment
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