CVE-2026-62243highCWE-297

CVE-2026-62243: high-severity vulnerability in netty

Netty 4.2.0 through 4.2.16 TLS Hostname Verification Bypass

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.7epss 0.2%
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+). In this configuration the OpenSSL client does not perform hostname verification, allowing a man-in-the-middle attacker to present a certificate issued for a different hostname that is accepted without validation. Fixed in 4.2.17.Final and 4.1.137.Final.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
netty · netty
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