High MSRC-CVE-2026-72978 1 CVE

Active Directory Federation Services (AD FS) Denial of Service Vulnerability

Published Sep 8, 2026 · Updated Sep 8, 2026

Vendor: Microsoft

Summary

Impact: Denial of Service. Microsoft rating: Important. Not known to be exploited — Exploitation Unlikely. Customer action: Required.

Details

Security updates
10.0.17763.9245 — https://support.microsoft.com/help/5122876
10.0.20348.5622 — https://support.microsoft.com/help/5122882
10.0.26100.33438 — https://support.microsoft.com/help/5122871
10.0.14393.9512 — https://support.microsoft.com/help/5123099
6.2.9200.26349 — https://support.microsoft.com/help/5123065
6.3.9600.23398 — https://support.microsoft.com/help/5123066

Vulnerabilities 1

Medium 5.9

CVE-2026-72978

Active Directory Federation Services (AD FS) Denial of Service Vulnerability

Allocation of resources without limits or throttling in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.

Microsoft Windows Server 2019 Windows Server 2019 (Server Core installation) Windows 10 Version 1809 Windows

Sep 8, 2026

Revision history

2026-09-08 #1
Information published.

References

CVE-2026-72978 Active Directory Federation Services (AD FS) Denial of Service Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72978
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss