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Microsoft Security Response CenterCVE-2026-96222

Active Directory Federation Services (AD FS) Spoofing Vulnerability

CriticalVendor CVSS 7.4 / 10 1 CVE Published Oct 13, 2026 at 7:00 AM UTC
Get alerts for System.Security.Cryptography.Xml on .NET 8.0 installed on Windows

Summary

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

Products covered

  • 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 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

Show 38 more products

  • 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)

  • Windows Server 2012 R2

  • Windows Server 2012 R2 (Server Core installation)

  • 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

Remediation

Release Notes Install KB5126651. Install KB5126655. Install KB5126646. Install KB5126868. Install KB5126836. Install KB5127689. Install KB5127690. Install KB5127691. Install KB5127692. Install KB5127693. Install KB5127694. Install KB5127696. Install KB5127660. Install KB5127664. Install KB5127666. Install KB5127685. Install KB5127683. Install KB5127687. Install KB5127667. Install KB5127668. Install KB5127684. Install KB5127686. Install KB5127688.

Vendor-listed fixes

  • 8.0.5

  • 10.0.17763.9376

  • 10.0.20348.5761

  • 10.0.26100.33650

  • 10.0.14393.9612

  • 6.3.9600.23470

  • 18.10.4

  • 17.14.42

Show 11 more fixes

  • 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0

  • 4.8.9363.0

  • 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.10008.0

  • 2.0.50727.9188 AND 3.0.30729.9171

  • 2.0.50727.8987 AND 3.0.30729.8982

  • 2.0.50727.8987 AND 3.0.30729.8982 AND 4.7.4150.0

  • 2.0.50727.9073 AND 3.0.30729.9070 AND 4.7.4150.0

  • 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0

  • 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.4811.0

  • 4.7.4150.0

  • 4.8.4811.0

CVEs in this advisory 1

CVE-2026-96222
Update history

What changed in later vendor updates

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

    • The vendor changed the advisory's last-updated date.

Updates

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  4. Confirmed at the source

    Our collector saw this advisory during a later source check.

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