CVE-2026-96222: Active Directory Federation Services (AD FS) Spoofing Vulnerability

Overview

Severity
High (CVSS 7.4)
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
Category
Spoofing
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Oct
Released
2026-10-13

Description

Improper certificate validation in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to have a deep understanding of the system. Successful exploitation is not guaranteed and depends on a combination of factors that might include the environment, system configuration, and the presence of additional security measures.

Affected Products (46)

Other

  • System.Security.Cryptography.Xml on .NET 8.0 installed on Windows
  • System.Security.Cryptography.Xml on .NET 8.0 installed on Linux
  • System.Security.Cryptography.Xml on .NET 8.0 installed on Mac OS

Windows

  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2025 (Server Core installation)
  • Windows Server 2025
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Developer Tools

  • Microsoft Visual Studio 2026 version 18.10
  • Microsoft Visual Studio 2022 version 17.14
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 21H2
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 22H2
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 24H2
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 25H2
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025
  • Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 23H2
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022
  • Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H2
  • Microsoft .NET Framework 3.5 on Windows 11 version 26H1
  • Microsoft .NET Framework 3.5 on Windows Server 2012
  • Microsoft .NET Framework 3.5 on Windows Server 2012 R2
  • Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 version 1607
  • Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016
  • Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2019
  • Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 version 1809
  • Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 1809
  • Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 21H2
  • Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 22H2
  • Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019
  • Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022
  • Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012
  • Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2
  • Microsoft .NET Framework 4.8 on Windows 10 version 1607
  • Microsoft .NET Framework 4.8 on Windows Server 2012
  • Microsoft .NET Framework 4.8 on Windows Server 2012 R2
  • Microsoft .NET Framework 4.8 on Windows Server 2016

Security Updates (25)

Acknowledgments

<a href="https://www.linkedin.com/in/vaishabernard/">Vaisha Bernard</a> with <a href="https://eye.security/">Eye Security</a>

Revision History

  • 2026-10-13: Information published.