CVE-2026-70005: Active Directory Federation Services (AD FS) Security Feature Bypass Vulnerability
Active Directory Federation Services (AD FS) Security Feature Bypass Vulnerability
Other sources
Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to bypass a security feature 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 10.0.26100.33650Patch 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 systems should be prioritized for assessment?
Prioritize Microsoft Windows Server 2019, Windows Server 2022, and Windows Server 2025 systems that run Active Directory Federation Services (AD FS) and are reachable over a network.
Does exploitation require an authenticated account or user interaction?
No. The provided vector indicates that exploitation does not require privileges or user interaction, but it does require network access and has high attack complexity.
What is the expected security impact?
The reported impact is integrity only; confidentiality and availability impacts are listed as none. Successful exploitation allows an unauthorized attacker to bypass an AD FS security feature.