io.netty/netty-handler: Netty: TLS hostname verification bypass via OpenSSL client path misconfiguration

A flaw was found in Netty io.netty:netty-handler. When using the SslProvider.OPENSSL client path with a plain X509TrustManager and without Unsafe-based trust-manager wrapping Java 25+, TLS hostname verification is disabled. This misconfiguration allows a man-in-the-middle attacker to present a...

CVE-2026-62243

Netty io.netty:netty-handler versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain non-extended X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable Java 25...

CVE-2026-62243

Netty io.netty:netty-handler versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain non-extended X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable Java 25...

EUVD-2026-64271

Netty io.netty:netty-handler versions from 4.2.0.Final through 4.2.16.Final and versions through 4.1.136.Final disable TLS hostname verification on the SslProvider.OPENSSL client path when a plain non-extended X509TrustManager is used and Unsafe-based trust-manager wrapping is unavailable Java 25...

PT-2026-79546

Name of the Vulnerable Software and Affected Versions Netty io.netty:netty-handler versions 4.2.0.Final through 4.2.16.Final Netty io.netty:netty-handler versions prior to 4.1.137.Final Description TLS hostname verification is disabled on the SslProvider.OPENSSL client path when a plain...