---
id: CVE-2026-83666
title: >-
  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.
summary: >-
  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.
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-362
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T21:18:33.030'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-83666'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83666'
    label: secure@microsoft.com
tags:
  - nvd
ingestedAt: '2026-10-13T19:43:29.078Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.