VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished CVSS 9.1 criticalEPSS 1% probability of exploitation in 30 days
Microsoft

CVE-2026-105794: MsQuic: Improper Certificate Validation in Microsoft.Native.Quic.MsQuic.OpenSSL

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
1%

EPSS score, percentile 62.8 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
9.1 Critical

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

  • < 2.4.20
  • >= 2.5.0, < 2.5.11
  • >= 2.6.0, < 2.6.1

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

microsoft msquic
StatusVersions
Affected< 2.4.20
Affected>= 2.5.0, < 2.5.11
Affected>= 2.6.0, < 2.6.1

Source: CVE List, as of . About the data.

About this vulnerability

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 s…

Summary: CVE record, as of .

  • CISA has not added CVE-2026-105794 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 6 Oct 2026.
  • The CVE record carries a CVSS v4.0 base score of 9.1 (Critical), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 1% (percentile 62.8), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

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.

Source: CVE List, as of . About the data.

Weakness

CWE-295
  • CWE-295: Improper Certificate Validation

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published

References

12

Known exploited Microsoft vulnerabilities

  • CVE-2026-96951: Microsoft Windows Command Injection Vulnerability (added )
  • CVE-2026-65660: Microsoft SharePoint Code Injection Vulnerability (added )
  • CVE-2026-81963: Microsoft Windows Link Following Vulnerability (added )
  • CVE-2026-85880: Microsoft Windows Heap-Based Buffer Overflow Vulnerability (added )
  • CVE-2019-1068: Microsoft SQL Server Remote Code Execution Vulnerability (added )