Windows NTLM Spoofing Vulnerability in Microsoft Products
CVE-2026-21249

3.3LOW

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1607
Windows 10 Version 1809
Windows 10 Version 21h2
Windows 10 Version 22h2
Vendor
CVE Published:
10 February 2026

What is CVE-2026-21249?

The Windows NTLM spoofing vulnerability enables attackers to gain unauthorized local access by manipulating file names or paths. By exploiting this weakness, attackers can craft malicious inputs that lead to authentication spoofing, potentially compromising sensitive information and system integrity. It is essential for users to apply the recommended patches from Microsoft to safeguard against this vulnerability.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8868

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8389

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.6937

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
3.3
Severity:
LOW
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.