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CVE-2026-40406: CWE-416: Use After Free in Microsoft Windows 10 Version 1607

0
High
VulnerabilityCVE-2026-40406cvecve-2026-40406cwe-416
Published: 05/12/2026 (05/12/2026, 16:58:43 UTC)
Source: CVE Database V5
Vendor/Project: Microsoft
Product: Windows 10 Version 1607

Description

Use after free in Windows TCP/IP allows an unauthorized attacker to disclose information over a network.

CVSS v3.1

Score 7.5high

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Affected software

Microsoft

Windows 10 Version 1607

Affected versions
>=10.0.14393.0 <10.0.14393.9140

Microsoft

Windows 10 Version 1809

Affected versions
>=10.0.17763.0 <10.0.17763.8755

Microsoft

Windows 10 Version 21H2

Affected versions
>=10.0.19044.0 <10.0.19044.7291

Microsoft

Windows 10 Version 22H2

Affected versions
>=10.0.19045.0 <10.0.19045.7417

Microsoft

Windows 11 version 23H2

Affected versions
>=10.0.22631.0 <10.0.22631.7079

Microsoft

Windows 11 Version 23H2

Affected versions
>=10.0.22631.0 <10.0.22631.7219

Microsoft

Windows 11 Version 24H2

Affected versions
>=10.0.26100.0 <10.0.26100.8457

Microsoft

Windows 11 Version 25H2

Affected versions
>=10.0.26200.0 <10.0.26200.8457

Microsoft

Windows 11 version 26H1

Affected versions
>=10.0.28000.0 <10.0.28000.2113

Microsoft

Windows Server 2012

Affected versions
>=6.2.9200.0 <6.2.9200.26079

Microsoft

Windows Server 2012 (Server Core installation)

Affected versions
>=6.2.9200.0 <6.2.9200.26079

Microsoft

Windows Server 2012 R2

Affected versions
>=6.3.9600.0 <6.3.9600.23181

Microsoft

Windows Server 2012 R2 (Server Core installation)

Affected versions
>=6.3.9600.0 <6.3.9600.23181

Microsoft

Windows Server 2016

Affected versions
>=10.0.14393.0 <10.0.14393.9140

Microsoft

Windows Server 2016 (Server Core installation)

Affected versions
>=10.0.14393.0 <10.0.14393.9140

Microsoft

Windows Server 2019

Affected versions
>=10.0.17763.0 <10.0.17763.8755

Microsoft

Windows Server 2019 (Server Core installation)

Affected versions
>=10.0.17763.0 <10.0.17763.8755

Microsoft

Windows Server 2022

Affected versions
>=10.0.20348.0 <10.0.20348.5139

Microsoft

Windows Server 2022, 23H2 Edition (Server Core installation)

Affected versions
>=10.0.25398.0 <10.0.25398.2330

Microsoft

Windows Server 2025

Affected versions
>=10.0.26100.0 <10.0.26100.32860

Microsoft

Windows Server 2025 (Server Core installation)

Affected versions
>=10.0.26100.0 <10.0.26100.32860

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 08/11/2026, 16:48:06 UTC

Technical Analysis

This vulnerability (CVE-2026-40406) involves a use-after-free condition in the Windows TCP/IP implementation on Windows 10 Version 1607 (build 10.0.14393.0). Exploitation can lead to unauthorized information disclosure over a network without requiring user interaction or privileges. Microsoft has published an official fix addressing this issue.

Potential Impact

The vulnerability allows an attacker to remotely disclose sensitive information without authentication or user interaction. There is no impact on integrity or availability. The confidentiality impact is high, potentially exposing sensitive data.

Mitigation Recommendations

An official patch is available from Microsoft. Users and administrators should apply the update provided in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40406 to remediate this vulnerability.

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Technical Details

Data Version
5.2
Assigner Short Name
microsoft
Date Reserved
2026-04-13T00:27:50.798Z
Cvss Version
3.1
State
PUBLISHED
Remediation Level
official-fix
Vendor Advisory Urls
[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40406","vendor":"Microsoft"}]

Threat ID: 6a036557cbff5d861008c9be

Added to database: 05/12/2026, 17:37:27 UTC

Last enriched: 08/11/2026, 16:48:06 UTC

Last updated: 09/14/2026, 22:01:33 UTC

Views: 137

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