{"id":"CVE-2026-100665","aliases":["GHSA-mj35-3qqm-q387"],"url":"https://o3.security/vulnerability/CVE-2026-100665","summary":"Netty 4.2.11 through 4.2.17 QUIC Hostname Verification Bypass","details":"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.","published":"2026-09-26T13:23:31.242Z","modified":"2026-09-27T03:47:25.119257934Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe","label":"netty/netty@09e72c4"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100665.json"},{"type":"FIX","url":"https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe"},{"type":"FIX","url":"https://github.com/netty/netty/commit/994e887ed9"},{"type":"ADVISORY","url":"https://github.com/netty/netty/security/advisories/GHSA-mj35-3qqm-q387"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100665"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/netty-4.2.11-through-4.2.17-quic-hostname-verification-bypass"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-27T03:47:25.119257934Z"}}