CVE-2026-34477
5.9 · MEDIUMOverview
CVE-2026-34477 is a medium-severity vulnerability affecting apache log4j. It was published on April 10, 2026 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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
Remediation
Check the references section for vendor advisories and patches from apache. Update log4j to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| apache | log4j | >= 2.12.0, < 2.25.4 | Affected |
References
Frequently Asked Questions
What is CVE-2026-34477?
CVE-2026-34477 is a medium-severity vulnerability affecting apache log4j. It was published on April 10, 2026 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
How severe is CVE-2026-34477?
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-34477?
Check the references section for vendor advisories and patches from apache. Update log4j to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-34477?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-34477 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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