CVE-2026-83674: Active Directory Federation Services (AD FS) Spoofing Vulnerability
Published Oct 13, 2026
·Updated
Active Directory Federation Services (AD FS) Spoofing Vulnerability
Other sources
Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.
— Microsoft
Affected Software
21 affected componentsFixes available
Microsoft Windows Server 2022<10.0.20348.5761
10.0.20348.5761
Microsoft Windows Server 2025<10.0.26100.33650
10.0.26100.33650
Microsoft Windows Server 2025<10.0.26100.33650
10.0.26100.33650
Microsoft Windows Server 2022<10.0.20348.5761
10.0.20348.5761
Microsoft Windows Server 2019<10.0.17763.9376
10.0.17763.9376
Microsoft Windows Server 2019<10.0.17763.9376
10.0.17763.9376
Microsoft Windows Server 2016<10.0.14393.9612
10.0.14393.9612
Microsoft Windows Server 2016<10.0.14393.9612
10.0.14393.9612
Microsoft Active Directory Federation Services
Microsoft Windows 10=1607, >=10.0.14393<10.0.14393.9612
10.0.14393.9612
Microsoft Windows 10=1809, >=10.0.17763<10.0.17763.9376
10.0.17763.9376
Microsoft Windows 10=1809, >=10.0.17763<10.0.17763.9376
10.0.17763.9376
Microsoft Windows 10=1607, >=10.0.14393<10.0.14393.9612
10.0.14393.9612
Microsoft Windows 10 1607<10.0.14393.9612
Microsoft Windows 10 1607<10.0.14393.9612
Microsoft Windows 10 1809<10.0.17763.9376
Microsoft Windows 10 1809<10.0.17763.9376
Microsoft Windows Server 2016<10.0.14393.9612
Microsoft Windows Server 2019<10.0.17763.9376
Microsoft Windows Server 2022<10.0.20348.5761
Microsoft Windows Server 2025<10.0.26100.33650
Remediation
Event History
Oct 13, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
CVE Published
via MITRE·07:00 PM
Data Sourced
via MITRE·07:00 PM
DescriptionSeverity
Data Sourced
via NVD·07:20 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
Which environments should be prioritized for assessment?
Prioritize deployments using Microsoft Active Directory Federation Services (AD FS), particularly where it runs on the listed Microsoft Windows 10 or Windows Server 2016, 2019, 2022, or 2025 platforms.
2
Does exploitation require an authenticated account or user interaction?
No. The provided vector indicates no privileges and no user interaction are required, and exploitation can be performed over the network. The attack complexity is rated high.