CVE-2026-100665

Netty versions from 4.2.11.Final before 4.2.18.Final contain an incomplete hostname verification fix in the QUIC certificate verification path when using a plain X509TrustManager. The BoringSSLCertificateVerifyCallback discards the SSLEngine for plain trust managers, preventing endpoint identification from running even when HTTPS verification is configured. Attackers on the network path can present a certificate chain for the wrong hostname that the plain trust manager accepts, bypassing hostname authentication for QUIC clients.

• https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe
• https://github.com/netty/netty/commit/994e887ed9
• https://github.com/netty/netty/security/advisories/GHSA-mj35-3qqm-q387
• https://www.vulncheck.com/advisories/netty-4.2.11-through-4.2.17-quic-hostname-verification-bypass