CVE-2026-85321

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

State: Published
Severity: 7.5 High
Published: Oct 13, 2026
Updated: Oct 31, 2026
Reserved: Sep 3, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-770 Allocation of Resources Without Limits or Throttling

Affected Products

Product	Versions
Windows Server 2012 R2Microsoft	6.3.9600.0 to before 6.3.9600.23470Affected
Windows Server 2012 R2 (Server Core installation)Microsoft	6.3.9600.0 to before 6.3.9600.23470Affected
Windows Server 2016Microsoft	10.0.14393.0 to before 10.0.14393.9612Affected
Windows Server 2016 (Server Core installation)Microsoft	10.0.14393.0 to before 10.0.14393.9612Affected
Windows Server 2019Microsoft	10.0.17763.0 to before 10.0.17763.9376Affected
Windows Server 2019 (Server Core installation)Microsoft	10.0.17763.0 to before 10.0.17763.9376Affected
Windows Server 2022Microsoft	10.0.20348.0 to before 10.0.20348.5761Affected
Windows Server 2025Microsoft	10.0.26100.0 to before 10.0.26100.33650Affected
Windows Server 2025 (Server Core installation)Microsoft	10.0.26100.0 to before 10.0.26100.33650Affected

References

Active Directory Federation Services (AD FS) Denial of Service Vulnerabilityvendor-advisorypatch

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