CVE-2026-50010

Summary

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.

Affected Software

VendorProductVersion RangeStatus
nettynetty>= 4.2.0.Final, < 4.2.15.Finalaffected
nettynetty< 4.1.135.Finalaffected

Weaknesses

  • CWE-347: CWE-347: Improper Verification of Cryptographic Signature

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

netty-handler: Netty: Improper trust manager handling leads to hostname verification bypass

Additional References

References