Windows DNS Server Remote Code Execution Vulnerability

Use after free in Windows DNS allows an unauthorized attacker to execute code over a network.

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8.1CVSS out of 10Critical severity

Scope

What the vendor says is affected

Windows Server 2022
Windows Server 2022 (Server Core installation)
Windows Server 2025 (Server Core installation)
Windows Server 2025

Versions the vendor lists as fixed

10.0.20348.5622
10.0.26100.33438

Next step

What the vendor recommends

Install KB5122882. Install KB5122871.

Review the complete instructions on the vendor's site

Timeline

When this advisory changed

Sep 8, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 8, 2026 at 7:15 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Sep 13, 2026 at 2:40 AM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory

CVE-2026-69858View CVSS, KEV, EPSS, and threat context

Source

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Vendor: Microsoft Security Response Center
Advisory ID: CVE-2026-69858
Last source check: Sep 13, 2026 at 2:40 AM UTC

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Your environment

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Test the update or mitigation through your normal change process.

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What the vendor says is affected

Versions the vendor lists as fixed

What the vendor recommends

When this advisory changed

CVEs named in this advisory

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