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EPSS 11.1%top 4.3%

CVE-2026-21249: CWE-73: External Control of File Name or Path in Microsoft Windows 10 Version 1607

0
Low
VulnerabilityCVE-2026-21249cvecve-2026-21249cwe-73gcve
Published: 02/10/2026 (02/10/2026, 17:51:42 UTC)
Source: CVE Database V5
Vendor/Project: Microsoft
Product: Windows 10 Version 1607

Description

External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.

CVSS v3.1

Score 3.3low

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

Affected software

Microsoft

Windows 10 Version 1607

Affected versions
>=10.0.14393.0 <10.0.14393.8868

Microsoft

Windows 10 Version 1809

Affected versions
>=10.0.17763.0 <10.0.17763.8389

Microsoft

Windows 10 Version 21H2

Affected versions
>=10.0.19044.0 <10.0.19044.6937

Microsoft

Windows 10 Version 22H2

Affected versions
>=10.0.19045.0 <10.0.19045.6937

Microsoft

Windows 11 version 22H3

Affected versions
>=10.0.22631.0 <10.0.22631.6649

Microsoft

Windows 11 Version 23H2

Affected versions
>=10.0.22631.0 <10.0.22631.6649

Microsoft

Windows 11 Version 24H2

Affected versions
>=10.0.26100.0 <10.0.26100.7840

Microsoft

Windows 11 Version 25H2

Affected versions
>=10.0.26200.0 <10.0.26200.7840

Microsoft

Windows 11 version 26H1

Affected versions
>=10.0.28000.0 <10.0.28000.1575

Microsoft

Windows 11 Version 26H1

Affected versions
>=10.0.28000.0 <10.0.28000.1575

Microsoft

Windows Server 2012 R2

Affected versions
>=6.3.9600.0 <6.3.9600.23022

Microsoft

Windows Server 2012 R2 (Server Core installation)

Affected versions
>=6.3.9600.0 <6.3.9600.23022

Microsoft

Windows Server 2016

Affected versions
>=10.0.14393.0 <10.0.14393.8868

Microsoft

Windows Server 2016 (Server Core installation)

Affected versions
>=10.0.14393.0 <10.0.14393.8868

Microsoft

Windows Server 2019

Affected versions
>=10.0.17763.0 <10.0.17763.8389

Microsoft

Windows Server 2019 (Server Core installation)

Affected versions
>=10.0.17763.0 <10.0.17763.8389

Microsoft

Windows Server 2022

Affected versions
>=10.0.20348.0 <10.0.20348.4773

Microsoft

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

Affected versions
>=10.0.25398.0 <10.0.25398.2149

Microsoft

Windows Server 2025

Affected versions
>=10.0.26100.0 <10.0.26100.32370

Microsoft

Windows Server 2025 (Server Core installation)

Affected versions
>=10.0.26100.0 <10.0.26100.32370

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 05/12/2026, 05:12:42 UTC

Technical Analysis

This vulnerability, tracked as CVE-2026-21249 and categorized under CWE-73 (External Control of File Name or Path), affects Windows 10 Version 1607 (build 10.0.14393.0). It involves improper handling of file names or paths in the NTLM authentication process, enabling a local attacker without privileges to perform spoofing. The CVSS 3.1 vector indicates low attack complexity, no privileges required, and user interaction needed, with limited confidentiality impact and no integrity or availability impact. Microsoft has published an official fix to remediate this vulnerability.

Potential Impact

The impact is limited to local spoofing attacks that could mislead users or processes by manipulating file names or paths. The confidentiality impact is low, and there is no impact on integrity or availability. No known exploits are reported in the wild.

Mitigation Recommendations

An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21249 to remediate this vulnerability.

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Technical Details

Data Version
5.2
Assigner Short Name
microsoft
Date Reserved
2025-12-11T21:02:05.736Z
Cvss Version
3.1
State
PUBLISHED
Remediation Level
official-fix
Vendor Advisory Urls
[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21249","vendor":"Microsoft"}]

Threat ID: 698b76004b57a58fa120a029

Added to database: 02/10/2026, 18:16:32 UTC

Last enriched: 05/12/2026, 05:12:42 UTC

Last updated: 09/10/2026, 22:11:37 UTC

Views: 217

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