{"id":"CVE-2026-105794","revision":"705c766547964125977f652d9ceb4099","records":[{"revision":"705c766547964125977f652d9ceb4099","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-105794","aliases":[],"title":"MsQuic: Improper Certificate Validation in Microsoft.Native.Quic.MsQuic.OpenSSL","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.","state":0,"publishedAt":"2026-10-06T14:14:54.483+00:00","modifiedAt":"2026-10-06T17:40:05.706+00:00","affected":[{"ecosystem":"Vendor product","name":"msquic","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"microsoft\",\n                    \"product\": \"msquic\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2.4.20\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2.5.0, < 2.5.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 2.6.0, < 2.6.1\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","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","score":9.1,"severity":"CRITICAL"}],"references":["https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7","https://github.com/microsoft/msquic/pull/6274","https://github.com/microsoft/msquic/pull/6275","https://github.com/microsoft/msquic/pull/6276","https://github.com/microsoft/msquic/pull/6277","https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412","https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91","https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81","https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83","https://github.com/microsoft/msquic/releases/tag/v2.4.20","https://github.com/microsoft/msquic/releases/tag/v2.5.11","https://github.com/microsoft/msquic/releases/tag/v2.6.1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-105794","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-105794","identifiers":["CVE-2026-105794"]},"retained":false,"historicalAffected":[]}],"coverage":[]}