CVEvulnerability
CVE-2026-105794
9.1 CRITICAL
Official page ↗
- Status
- Awaiting Analysis
- Published
- 2026-10-06
- Last modified
- 2026-10-06
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 9.1 CRITICAL — 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Weaknesses
- CWE-295
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.
Related
Weakness · CWE (1)
- CWE-295 Improper Certificate Validation weakness
References
- https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412 github.com
- https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91 github.com
- https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81 github.com
- https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83 github.com
- https://github.com/microsoft/msquic/pull/6274 github.com
- https://github.com/microsoft/msquic/pull/6275 github.com
- https://github.com/microsoft/msquic/pull/6276 github.com
- https://github.com/microsoft/msquic/pull/6277 github.com
- https://github.com/microsoft/msquic/releases/tag/v2.4.20 github.com
- https://github.com/microsoft/msquic/releases/tag/v2.5.11 github.com
- https://github.com/microsoft/msquic/releases/tag/v2.6.1 github.com
- https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7 github.com