CVE-2026-69631: Windows DNS Denial of Service Vulnerability

Published Sep 8, 2026
·
Updated

Integer overflow or wraparound in Windows DNS allows an unauthorized attacker to deny service over a network.

Other sources

Windows DNS Denial of Service Vulnerability

Microsoft

Affected Software

16 affected componentsFixes available
Microsoft Windows Server 2016<10.0.14393.9512
10.0.14393.9512
Microsoft Windows Server 2012 R2<6.3.9600.23397
6.3.9600.23397
Microsoft Windows 10=1607
10.0.14393.9512
Microsoft Windows Server 2012 R2<6.3.9600.23397
6.3.9600.23397
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows Server 2016<10.0.14393.9512
10.0.14393.9512
Microsoft Windows Server 2012<6.2.9200.26349
6.2.9200.26349
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows Server 2012<6.2.9200.26349
6.2.9200.26349
Microsoft Windows 10=1607
10.0.14393.9512
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.14393.9512Patch KB5123099
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.3.9600.23397Patch KB5123066
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.2.9200.26349Patch KB5123065
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.17763.9245Patch KB5122876
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.20348.5622Patch KB5122882
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.33438Patch KB5122871

Event History

Sep 8, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:11 PM
Data Sourced
via MITRE·05:11 PM
DescriptionSeverity
Data Sourced
via NVD·06:19 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

Which systems are exposed to this issue?

The affected products listed are Microsoft Windows 10 and Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025. Exposure is relevant where the Windows DNS component is reachable over the network.

2

Does exploitation require authentication or user interaction?

No. The supplied vector indicates network-based exploitation with low attack complexity, no privileges required, and no user interaction required.

3

What is the expected impact of a successful attack?

A successful attack can deny service through an integer overflow or wraparound in Windows DNS. The provided impact metrics indicate availability impact only, with no stated confidentiality or integrity impact.

Contact

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