CVE-2026-212493.3LowCWE-73

CVE-2026-21249: Windows NTLM Spoofing Vulnerability

Microsoft · Windows 10 Version 1607

Vendor fix available · Affected: Microsoft Windows 10 Version 1607 · Exploitation: likely to be exploited (10% or more)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

11.3%probability of exploitation in the next 30 days

96th percentile

050100

Higher than 96% of scored CVEs

3.3LowCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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

Affected products20

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Microsoft · Windows 10 Version 1607from 10.0.14393.0 before 10.0.14393.8868
Microsoft · Windows 10 Version 1809from 10.0.17763.0 before 10.0.17763.8389
Microsoft · Windows 10 Version 21H2from 10.0.19044.0 before 10.0.19044.6937
Microsoft · Windows 10 Version 22H2from 10.0.19045.0 before 10.0.19045.6937
Microsoft · Windows 11 version 22H3from 10.0.22631.0 before 10.0.22631.6649
Microsoft · Windows 11 Version 23H2from 10.0.22631.0 before 10.0.22631.6649
Microsoft · Windows 11 Version 24H2from 10.0.26100.0 before 10.0.26100.7840
Microsoft · Windows 11 Version 25H2from 10.0.26200.0 before 10.0.26200.7840
Microsoft · Windows 11 version 26H1from 10.0.28000.0 before 10.0.28000.1575
Microsoft · Windows 11 Version 26H1from 10.0.28000.0 before 10.0.28000.1575
Microsoft · Windows Server 2012 R2from 6.3.9600.0 before 6.3.9600.23022
Microsoft · Windows Server 2012 R2 (Server Core installation)from 6.3.9600.0 before 6.3.9600.23022
Microsoft · Windows Server 2016from 10.0.14393.0 before 10.0.14393.8868
Microsoft · Windows Server 2016 (Server Core installation)from 10.0.14393.0 before 10.0.14393.8868
Microsoft · Windows Server 2019from 10.0.17763.0 before 10.0.17763.8389
Microsoft · Windows Server 2019 (Server Core installation)from 10.0.17763.0 before 10.0.17763.8389
Microsoft · Windows Server 2022from 10.0.20348.0 before 10.0.20348.4773
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)from 10.0.25398.0 before 10.0.25398.2149
Microsoft · Windows Server 2025from 10.0.26100.0 before 10.0.26100.32370
Microsoft · Windows Server 2025 (Server Core installation)from 10.0.26100.0 before 10.0.26100.32370

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Likely to be exploited (10% or more). EPSS gives it a 10% or higher chance of exploitation in the next 30 days.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: External Control of File Name or Path · File and Path Handling
Vendor: Microsoft
Published: February 2026
Band: Likely to be exploited (10% or more), February 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-21249 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.