CVE-2026-105794
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.
INFO
Published Date :
Oct. 6, 2026, 3:17 p.m.
Last Modified :
Oct. 6, 2026, 3:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-105794
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update MsQuic to version 2.4.20 or later.
- Update MsQuic to version 2.5.11 or later.
- Update MsQuic to version 2.6.1 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-105794.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-105794 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-105794
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-105794 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-105794 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Oct. 06, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CWE CWE-295 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/105xxx/CVE-2026-105794.json">CVE-2026-105794</a> Added Reference https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412 Added Reference https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91 Added Reference https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81 Added Reference https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83 Added Reference https://github.com/microsoft/msquic/pull/6274 Added Reference https://github.com/microsoft/msquic/pull/6275 Added Reference https://github.com/microsoft/msquic/pull/6276 Added Reference https://github.com/microsoft/msquic/pull/6277 Added Reference https://github.com/microsoft/msquic/releases/tag/v2.4.20 Added Reference https://github.com/microsoft/msquic/releases/tag/v2.5.11 Added Reference https://github.com/microsoft/msquic/releases/tag/v2.6.1 Added Reference https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7