CVE Catalog

CVE-2026-105794

CriticalCVSS 9.1
Published: Updated: Translated: NVD NIST

Summary

MsQuic prior to versions 2.4.20, 2.5.11, and 2.6.1 contains a vulnerability where 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 present a certificate that does not match the intended hostname and spoof the server in a man-in-the-middle attack. The Schannel backend is not affected.

Risk Assessment

Risk of man-in-the-middle attack where an attacker can impersonate the server and intercept or modify client communication.

Recommendation

Upgrade MsQuic to version 2.4.20, 2.5.11, or 2.6.1 depending on the version in use.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS