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+). 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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/netty/netty/security/advisories/GHSA-p85m-gvr3-788c
https://www.vulncheck.com/advisories/netty-through-tls-hostname-verification-bypass

Configurations

No configuration.

History

14 Oct 2026, 19:10

Type	Values Removed	Values Added
Summary		(es) Netty (io.netty:netty-handler) versiones desde 4.2.0.Final hasta 4.2.16.Final y versiones hasta 4.1.136.Final deshabilitan la verificación de nombre de host TLS en la ruta del cliente SslProvider.OPENSSL cuando se utiliza un X509TrustManager simple (no extendido) y el encapsulamiento del gestor de confianza basado en Unsafe no está disponible (Java 25+). En esta configuración, el cliente OpenSSL no realiza la verificación de nombre de host, permitiendo a un atacante man-in-the-middle presentar un certificado emitido para un nombre de host diferente que es aceptado sin validación. Corregido en 4.2.17.Final y 4.1.137.Final.

Information

Published : 2026-08-22 13:16

Updated : 2026-10-14 19:10

NVD link : CVE-2026-62243

Mitre link : CVE-2026-62243

CVE.ORG link : CVE-2026-62243

JSON object : View

Products Affected

No product.

CWE

CWE-297

Improper Validation of Certificate with Host Mismatch

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