CVE-2026-75595

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route's mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

History

26 Oct 2026, 10:10

Type Values Removed Values Added
Summary
  • (es) Netty es un framework de aplicación de red asíncrono y basado en eventos. Antes de las versiones 4.1.137.Final y 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode comprueba el desplazamiento incorrecto antes de leer la cabecera de handshake TLS de cuatro bytes, por lo que un ClientHello cuya cabecera de handshake abarca registros puede causar una IndexOutOfBoundsException e invocar select(ctx, null). Esto selecciona el SslContext predeterminado en lugar del contexto específico de SNI. En implementaciones donde clientAuth=REQUIRE por SNI es la única puerta de TLS mutuo, el SslContext predeterminado usa clientAuth=NONE o clientAuth=OPTIONAL, y no existe verificación de certificado a nivel de aplicación, un atacante remoto no autenticado puede eludir el requisito de TLS mutuo de la ruta protegida. Este problema está solucionado en las versiones 4.1.137.Final y 4.2.17.Final.

22 Sep 2026, 19:33

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 9.1
CPE cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
References () https://github.com/netty/netty/commit/1b5abc6443b63726c72cdd285af2feb7ddbb8ff7 - () https://github.com/netty/netty/commit/1b5abc6443b63726c72cdd285af2feb7ddbb8ff7 - Patch
References () https://github.com/netty/netty/commit/9e0519239108a69b7e9bbc5e9182ee139a0d7961 - () https://github.com/netty/netty/commit/9e0519239108a69b7e9bbc5e9182ee139a0d7961 - Patch
References () https://github.com/netty/netty/pull/17213 - () https://github.com/netty/netty/pull/17213 - Issue Tracking, Patch
References () https://github.com/netty/netty/pull/17217 - () https://github.com/netty/netty/pull/17217 - Issue Tracking, Patch
References () https://github.com/netty/netty/releases/tag/netty-4.1.137.Final - () https://github.com/netty/netty/releases/tag/netty-4.1.137.Final - Release Notes
References () https://github.com/netty/netty/releases/tag/netty-4.2.17.Final - () https://github.com/netty/netty/releases/tag/netty-4.2.17.Final - Release Notes
References () https://github.com/netty/netty/security/advisories/GHSA-c4c3-7fpv-j4q5 - () https://github.com/netty/netty/security/advisories/GHSA-c4c3-7fpv-j4q5 - Vendor Advisory
First Time Netty netty
Netty

Information

Published : 2026-08-19 21:17

Updated : 2026-10-26 10:10


NVD link : CVE-2026-75595

Mitre link : CVE-2026-75595

CVE.ORG link : CVE-2026-75595


JSON object : View

Products Affected

netty

  • netty
CWE
CWE-754

Improper Check for Unusual or Exceptional Conditions