Summary
Apache Log4j does not verify the TLS hostname in its Socket Appender
The Socket Appender in Apache Log4j Core versions 2.0-beta9 through 2.25.2 does not perform TLS hostname verification of the peer certificate, even when the verifyHostName configuration attribute or the log4j2.sslVerifyHostName system property is set to true.
This issue may allow a man-in-the-middle attacker to intercept or redirect log traffic under the following conditions:
- The attacker is able to intercept or redirect network traffic between the client and the log receiver.
- The attacker can present a server certificate issued by a certification authority trusted by the Socket Appender’s configured trust store (or by the default Java trust store if no custom trust store is configured).
Users are advised to upgrade to Apache Log4j Core version 2.25.3, which addresses this issue.
As an alternative mitigation, the Socket Appender may be configured to use a private or restricted trust root to limit the set of trusted certificates.
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-68161? CVE-2025-68161 is a medium-severity security vulnerability in org.apache.logging.log4j:log4j-core (maven), affecting versions >= 2.0-beta9, < 2.25.3. It is fixed in 2.25.3.
- Which versions of org.apache.logging.log4j:log4j-core are affected by CVE-2025-68161? org.apache.logging.log4j:log4j-core (maven) versions >= 2.0-beta9, < 2.25.3 is affected.
- Is there a fix for CVE-2025-68161? Yes. CVE-2025-68161 is fixed in 2.25.3. Upgrade to this version or later.
- Is CVE-2025-68161 exploitable, and should I be worried? Whether CVE-2025-68161 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-68161 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-68161? Upgrade
org.apache.logging.log4j:log4j-coreto 2.25.3 or later.