CVE-2026-62817

Analyzed Analyzed - Analysis Complete

Out-of-bounds Write in Windows DNS

Publication date: 2026-08-11

Last updated on: 2026-08-17

Assigner: Microsoft Corporation

Description

Out-of-bounds write in Windows DNS allows an unauthorized attacker to execute code over an adjacent network.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-11

Last Modified

2026-08-17

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-62817

EUVD

EUVD-2026-56394

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_server_2019	to 10.0.17763.9121 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This is an out-of-bounds write vulnerability in Windows DNS that allows an unauthorized attacker to execute arbitrary code over an adjacent network. It occurs when software writes data past the end of allocated memory buffers in the DNS service.

Detection Guidance

This vulnerability is specific to Windows DNS and requires patching via Microsoft updates. Detection typically involves checking DNS server versions against the patched release. Use PowerShell: Get-WindowsPackage -Online | Where-Object {$_.PackageName -like "*Windows-DNS*"} to verify installed versions. Compare against Microsoft's advisory for the fixed build number.

Impact Analysis

An attacker could exploit this to run malicious code on your system, potentially taking control of your device. Since it works over a network, the attacker doesn't need direct access to your machine.

Compliance Impact

This vulnerability allows remote code execution via an out-of-bounds write in Windows DNS, which could lead to unauthorized access or data breaches. Such breaches may violate GDPR's data protection requirements or HIPAA's safeguards for protected health information, depending on the affected system and data.

Mitigation Strategies

Apply the latest security update from Microsoft for Windows DNS to patch the out-of-bounds write vulnerability. Monitor Microsoft's advisory for updates and ensure network segmentation to limit adjacent network access to DNS servers.

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