Windows DNS Race Condition Denial of Service

Publication date: 2026-09-08

Last updated on: 2026-09-24

Assigner: Microsoft Corporation

Description

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

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-08

Last Modified

2026-09-24

Generated

2026-09-29

AI Q&A

2026-09-09

EPSS Evaluated

2026-09-27

NVD

CVE-2026-70091

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_dns	*

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 Windows DNS where improper synchronization during concurrent execution allows unauthorized attackers to disrupt service over a network by causing a denial of service.

Impact Analysis

An attacker could exploit this to crash or slow down DNS services, leading to network downtime, disrupted internet access, or failed connections to critical services.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft to patch the DNS race condition vulnerability. Monitor network traffic for unusual DNS service disruptions or crashes.

Hi! I’m here to help you understand CVE-2026-70091. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70