{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-100665","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-09-26T02:33:59.039Z","datePublished":"2026-09-26T13:23:31.242Z","dateUpdated":"2026-09-27T16:27:50.282Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-09-27T16:27:50.282Z"},"datePublic":"2026-09-10T00:00:00.000Z","title":"Netty 4.2.11 through 4.2.17 QUIC Hostname Verification Bypass","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Certificate Validation","cweId":"CWE-295","type":"CWE"}]}],"affected":[{"vendor":"netty","product":"netty","defaultStatus":"unaffected","packageURL":"pkg:maven/io.netty/netty-codec-classes-quic","versions":[{"version":"4.2.11.Final","status":"affected","versionType":"custom","lessThan":"4.2.18.Final"},{"version":"4.2.18.Final","status":"unaffected","versionType":"custom"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2.11.final","versionEndExcluding":"4.2.18.final"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/netty/netty/security/advisories/GHSA-mj35-3qqm-q387","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-mj35-3qqm-q387)"},{"url":"https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/netty/netty/commit/994e887ed9","tags":["patch"],"name":"Patch Commit"},{"name":"VulnCheck Advisory: Netty 4.2.11 through 4.2.17 QUIC Hostname Verification Bypass","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/netty-4.2.11-through-4.2.17-quic-hostname-verification-bypass"}],"credits":[{"lang":"en","value":"rexpository","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}