CVE-2026-83674: Active Directory Federation Services (AD FS) Spoofing Vulnerability
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
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17763.9376Patch KB5126651
Event History
Frequently Asked Questions
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.
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.