CVE-2026-105794

CRITICALCVSS 9.1/10

Last modified

CVE-2026-105794 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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.

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
microsoftmsquic< 2.4.20; >= 2.5.0, < 2.5.11; >= 2.6.0, < 2.6.1

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-105794?
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.
How severe is CVE-2026-105794?
CVE-2026-105794 has a CVSS score of 9.1/10 (CRITICAL severity).
How do I fix CVE-2026-105794?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-105794?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST