CVE-2026-83991: Windows Cloud Files Mini Filter Driver Tampering Vulnerability
Published Sep 8, 2026
·Updated
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
Other sources
Windows Cloud Files Mini Filter Driver Tampering Vulnerability
— Microsoft
Affected Software
41 affected componentsFixes available
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows 11=24H2
10.0.26100.9445
Microsoft Windows 11=25H2
10.0.26200.9445
Microsoft Windows 11=26H1
10.0.28000.2954
Microsoft Windows 11=24H2
10.0.26100.9445
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows 11=23H2
10.0.22631.7582
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows 11=26H1
10.0.28000.2954
Microsoft Windows 11=23H2
10.0.22631.7582
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows 11=25H2
10.0.26200.9445
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 11 23h2<10.0.22631.7582
Microsoft Windows 11 23h2<10.0.22631.7582
Microsoft Windows 11 24h2<10.0.26100.9445
Microsoft Windows 11 24h2<10.0.26100.9445
Microsoft Windows 11 25h2<10.0.26200.9445
Microsoft Windows 11 25h2<10.0.26200.9445
Microsoft Windows 11 26h1<10.0.28000.2954
Microsoft Windows 11 26h1<10.0.28000.2954
Microsoft Windows Server 2019<10.0.17763.9245
Microsoft Windows Server 2022<10.0.20348.5622
Microsoft Windows Server 2025<10.0.26100.33438
Remediation
Event History
Sep 8, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·05:14 PM
Data Sourced
via MITRE·05:14 PM
DescriptionSeverity
Data Sourced
via NVD·06:21 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
Which systems are listed as affected?
The listed affected products are Microsoft Windows 10, Windows 11, Windows Server 2019, Windows Server 2022, and Windows Server 2025.
2
What access does an attacker need to exploit this issue?
Exploitation requires local access and low privileges on the affected system. No user interaction is required.