Heap-based Buffer Overflow in Windows Cloud Files Mini Filter Driver by Microsoft
CVE-2026-20940

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 22h2
Windows 11 Version 22h3
Windows 11 Version 23h2
Windows Server 2019 (server Core Installation)
Vendor
CVE Published:
13 January 2026

What is CVE-2026-20940?

The Windows Cloud Files Mini Filter Driver is susceptible to a heap-based buffer overflow vulnerability, which may allow an authorized attacker to gain elevated privileges locally. This flaw can be exploited to potentially execute arbitrary code with higher permissions, making it critical for users to apply available security patches to mitigate the risk.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8783

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8276

Windows 10 Version 21H2 ARM64-based Systems 10.0.19044.0 < 10.0.19044.6809

References

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

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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