{"id":"CVE-2026-105794","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-105794","generatedAt":"2026-10-23T21:18:20.777Z","title":"MsQuic is a cross-platform C implementation of the IETF QUIC protocol exposed to C, C++, C#, and Rust.","description":"MsQuic is a cross-platform C implementation of the IETF QUIC protocol exposed to C, C++, C#, and Rust. Prior to 2.4.20, 2.5.11, and 2.6.1, MsQuic clients using the OpenSSL or QuicTLS TLS backend do not properly verify that a server certificate matches the intended target server hostname. An on-path attacker can therefore present a certificate that does not match the intended target hostname and spoof the server in a man-in-the-middle attack. The Schannel backend is not affected. This issue is fixed in versions 2.4.20, 2.5.11, and 2.6.1.","published":"2026-10-06T15:17:16.000Z","lastModified":"2026-10-06T18:16:47.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":9.1,"severity":"CRITICAL","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/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":0.01001,"percentile":0.62494,"date":"2026-10-22","history":[{"date":"2026-10-07","score":0.01001,"percentile":0.61685}]},"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 (1.00%). 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":"2026-10-06T15:17:16.000Z","detail":{"score":"9.1","severity":"CRITICAL","publishedAt":"2026-10-06T15:17:16.260Z"},"summary":"New CVE, critical severity (CVSS 9.1)."}],"references":[{"url":"https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/pull/6274","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/pull/6275","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/pull/6276","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/pull/6277","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/releases/tag/v2.4.20","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/releases/tag/v2.5.11","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/releases/tag/v2.6.1","source":"security-advisories@github.com"},{"url":"https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-105794","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."}