CVE-2026-83666

Analyzed Analyzed - Analysis Complete

Race Condition in Active Directory Certificate Services Elevates Privileges

Publication date: 2026-10-13

Last updated on: 2026-10-29

Assigner: Microsoft Corporation

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges locally.

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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-2026-83666

EUVD

EUVD-2026-99320

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9612 (exc)
microsoft	windows_10_1607	to 10.0.14393.9612 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
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-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Executive Summary

This is a race condition vulnerability in Active Directory Certificate Services (AD CS) where improper synchronization during concurrent execution allows an authorized attacker to elevate their privileges locally.

Impact Analysis

An attacker with local access could exploit this to gain higher privileges, potentially allowing them to take control of affected systems or access sensitive data.

Compliance Impact

This vulnerability allows local privilege escalation in Active Directory Certificate Services (AD CS), which could lead to unauthorized access to sensitive systems or data. For compliance standards like GDPR and HIPAA, such unauthorized access risks data breaches, potentially violating confidentiality and integrity requirements.

Mitigation Strategies

Apply the latest security updates from Microsoft for Active Directory Certificate Services (AD CS) to address the race condition vulnerability. Monitor Microsoft's security advisories for patches and follow their recommended mitigation steps.

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