{"id":"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.","aliases":["GHSA-mj35-3qqm-q387"],"modified":"2026-09-30T03:46:41.713976300Z","published":"2026-09-26T13:23:31.242Z","database_specific":{"cwe_ids":["CWE-295"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100665.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100665.json"},{"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"},{"type":"FIX","url":"https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe"},{"type":"FIX","url":"https://github.com/netty/netty/commit/994e887ed9"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/netty/netty","events":[{"introduced":"c94a8180e749f694fb76963dd494bae17c31aff6"},{"fixed":"2521f494432e27415a567d3a81a9eb907abf20b3"},{"fixed":"09e72c4fd8007277121ed48db63a124b112b96fe"},{"fixed":"994e887ed9"}],"database_specific":{"extracted_events":[{"introduced":"4.2.11.Final"},{"fixed":"4.2.18.Final"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["netty-clang-bin","netty-4.2.17.Final","netty-4.2.16.Final","netty-4.2.15.Final","netty-4.2.14.Final","netty-4.2.13.Final","netty-4.2.12.Final","netty-4.2.11.Final"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100665.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"}]}