{"id":"CVE-2026-100665","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100665","generatedAt":"2026-10-28T05:27:52.569Z","title":"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.","description":"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":"2026-09-26T14:16:50.000Z","lastModified":"2026-10-02T16:16:42.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-295"],"affected":[],"epss":{"score":0.00367,"percentile":0.30429,"date":"2026-10-27","history":[{"date":"2026-09-27","score":0.00291,"percentile":0.19397}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.37%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-26T14:16:50.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-09-26T14:16:49.677Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://github.com/netty/netty/commit/09e72c4fd8007277121ed48db63a124b112b96fe","source":"disclosure@vulncheck.com"},{"url":"https://github.com/netty/netty/commit/994e887ed9","source":"disclosure@vulncheck.com"},{"url":"https://github.com/netty/netty/security/advisories/GHSA-mj35-3qqm-q387","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/netty-4.2.11-through-4.2.17-quic-hostname-verification-bypass","source":"disclosure@vulncheck.com"},{"url":"https://github.com/netty/netty/security/advisories/GHSA-mj35-3qqm-q387","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100665","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}