Netty up to 4.1 SimpleTrustManagerFactory.engineGetTrustManagers signature verification

Summaryinfo

A vulnerability labeled as problematic has been found in Netty up to 4.1. The affected element is the function SimpleTrustManagerFactory.engineGetTrustManagers. Executing a manipulation can lead to signature verification. This vulnerability appears as CVE-2026-50010. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Netty up to 4.1. It has been declared as problematic. This vulnerability affects the function SimpleTrustManagerFactory.engineGetTrustManagers. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect confidentiality. CVE summarizes:

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.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. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

The advisory is available at github.com. This vulnerability was named CVE-2026-50010 since 06/03/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 4.1.135.Final or 4.2.15.Final eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1814). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Open Source Netty

Productinfo

Name

• Netty

Version

• 4.0
• 4.1

Website

• Product: https://github.com/netty/netty/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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