MsQuic: Improper Certificate Validation in Microsoft.Native.Quic.MsQuic.OpenSSL
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.
CVE-2026-105794
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-105794
msquic
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "microsoft",
"product": "msquic",
"versions": [
{
"status": "affected",
"version": "< 2.4.20"
},
{
"status": "affected",
"version": ">= 2.5.0, < 2.5.11"
},
{
"status": "affected",
"version": ">= 2.6.0, < 2.6.1"
}
]
}
]- Related CVEs
- CVE-2026-105794
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #9469 · Revision 1
- Added to Heist Feed
- Publisher date