---
id: CVE-2026-61920
title: >-
  Concurrent execution using shared resource with improper synchronization
  ('race condition') in Windows DNS allows an authorized attacker to execute
  code over a network.
summary: >-
  Concurrent execution using shared resource with improper synchronization
  ('race condition') in Windows DNS allows an authorized attacker to execute
  code over a network.
severity: medium
cvss: 6.6
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-362
  - CWE-416
published: '2026-08-11'
updated: '2026-08-16'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61920'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-61920'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00519
epssPercentile: 0.4158
ingestedAt: '2026-08-16T19:41:34.060Z'
vendor: Microsoft
product: Windows Server 2012 R2
affected:
  - windows_server_2012_r2 >= 6.3.9600.0 < 6.3.9600.23338
  - >-
    windows_server_2012_r2_server_core_installation >= 6.3.9600.0 <
    6.3.9600.23338
  - windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9418
  - >-
    windows_server_2016_server_core_installation >= 10.0.14393.0 <
    10.0.14393.9418
  - windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9121
  - >-
    windows_server_2019_server_core_installation >= 10.0.17763.0 <
    10.0.17763.9121
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5499
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33296
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.33296
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-12T03:57:30.453243Z'
---

## Overview

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows DNS allows an authorized attacker to execute code over a network.

## Remediation

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