CVE-2026-85321

Analyzed Analyzed - Analysis Complete

Allocation of Resources Without Limits in Active Directory Federation Services

Publication date: 2026-10-13

Last updated on: 2026-10-29

Assigner: Microsoft Corporation

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.

CVSS Scores

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Meta Information

Published

2026-10-13

Last Modified

2026-10-29

Generated

2026-11-08

AI Q&A

2026-10-14

EPSS Evaluated

2026-11-07

NVD

CVE-2026-85321

EUVD

EUVD-2026-99461

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2016	to 10.0.14393.9612 (exc)
microsoft	windows_server_2019	to 10.0.17763.9376 (exc)
microsoft	windows_server_2025	to 10.0.26100.33650 (exc)
microsoft	windows_server_2022	to 10.0.20348.5761 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-770	The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Attack-Flow Graph

Executive Summary

This vulnerability involves Active Directory Federation Services (AD FS) not properly limiting or throttling resource allocation. An unauthorized attacker can exploit this to send excessive requests, causing a denial of service over the network.

Impact Analysis

An attacker could disrupt services by overwhelming AD FS with requests, leading to service unavailability for legitimate users. This may cause downtime for authentication and identity management services.

Compliance Impact

This vulnerability allows unauthorized denial of service attacks on AD FS, which could disrupt authentication and authorization services. Such disruptions may impact compliance with GDPR (availability requirements) and HIPAA (access control and system availability).

Mitigation Strategies

Apply the latest security updates from Microsoft for AD FS to address the resource allocation issue. Monitor network traffic for unusual patterns indicating a denial of service attempt. Ensure AD FS servers are not exposed to untrusted networks without proper protections.

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EPSS Chart

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