CVE-2026-105794MsQuic: Improper Certificate Validation in Microsoft.Native.Quic.MsQuic.OpenSSL
Updated under an hour ago ()
Does this affect you?
It affects microsoft msquic. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 1.00%, higher than 62% of scored CVEs.
Do this next
Free account, 1 product
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.
- CVSS
- 9.1 CRITICAL (v4.0, CNA)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
- Weakness (CWE)
- CWE-295
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 1.00% (percentile 62)
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 6, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
microsoft msquic microsoft:msquic (from the name) | before 2.4.20; from 2.5.0, < 2.5.11; from 2.6.0, < 2.6.1 | CNA record |
References
- https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7x-refsource-confirm
- https://github.com/microsoft/msquic/pull/6274x-refsource-misc
- https://github.com/microsoft/msquic/pull/6275x-refsource-misc
- https://github.com/microsoft/msquic/pull/6276x-refsource-misc
- https://github.com/microsoft/msquic/pull/6277x-refsource-misc
- https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412x-refsource-misc
- https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91x-refsource-misc
- https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81x-refsource-misc
- https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83x-refsource-misc
- https://github.com/microsoft/msquic/releases/tag/v2.4.20x-refsource-misc
- https://github.com/microsoft/msquic/releases/tag/v2.5.11x-refsource-misc
- https://github.com/microsoft/msquic/releases/tag/v2.6.1x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.