CVE-2026-50010 is a high-severity security vulnerability in io.netty:netty-handler (maven), affecting versions >= 4.2.0.Final, < 4.2.15.Final. It is fixed in 4.2.15.Final, 4.1.135.Final.
SimpleTrustManagerFactory.engineGetTrustManagers() and related paths wrap any user-supplied plain X509TrustManager in X509TrustManagerWrapper, which extends X509ExtendedTrustManager but implements the 3-arg checkServerTrusted(chain, authType, SSLEngine) by discarding the SSLEngine and calling the 2-arg delegate. Because the object now IS an X509ExtendedTrustManager, neither SunJSSE's internal AbstractTrustManagerWrapper nor Netty's own OpenSslX509TrustManagerWrapper will re-wrap it to add endpoint-identification. Consequently, even though Netty 4.2 sets endpointIdentificationAlgorithm="HTTPS" by default, a client built with SslContextBuilder.forClient().trustManager(somePlainX509TrustManager) performs no hostname verification at all.
CVE-2026-50010 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (4.2.15.Final, 4.1.135.Final). Upgrading removes the vulnerable code path.
maven
io.netty:netty-handler (>= 4.2.0.Final, < 4.2.15.Final)io.netty:netty-handler (<= 4.1.134.Final)io.netty:netty-handler → 4.2.15.Final (maven)io.netty:netty-handler → 4.1.135.Final (maven)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 instead of chasing every advisory.
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Upgrade the following packages to resolve this vulnerability:
io.netty:netty-handler to 4.2.15.Final or laterio.netty:netty-handler to 4.1.135.Final or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-50010 is a high-severity security vulnerability in io.netty:netty-handler (maven), affecting versions >= 4.2.0.Final, < 4.2.15.Final. It is fixed in 4.2.15.Final, 4.1.135.Final.
CVE-2026-50010 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
io.netty:netty-handler (maven) versions >= 4.2.0.Final, < 4.2.15.Final is affected.
Yes. CVE-2026-50010 is fixed in 4.2.15.Final, 4.1.135.Final. Upgrade to this version or later.
Whether CVE-2026-50010 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
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.
io.netty:netty-handler to 4.2.15.Final or laterio.netty:netty-handler to 4.1.135.Final or later