CVE-2026-83991

Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83991	Vendor Advisory Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:microsoft:windows_10_1809:::::::x64:*
	cpe:2.3:o:microsoft:windows_10_1809:::::::x86:*
	cpe:2.3:o:microsoft:windows_10_21h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_10_21h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_10_21h2:::::::x86:*
	cpe:2.3:o:microsoft:windows_10_22h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_10_22h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_10_22h2:::::::x86:*
	cpe:2.3:o:microsoft:windows_11_23h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_23h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_24h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_24h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::x64:*
	cpe:2.3:o:microsoft:windows_server_2019::::::::
	cpe:2.3:o:microsoft:windows_server_2022::::::::
	cpe:2.3:o:microsoft:windows_server_2025::::::::

History

No history.

Information

Published : 2026-09-08 18:21

Updated : 2026-09-09 20:14

NVD link : CVE-2026-83991

Mitre link : CVE-2026-83991

CVE.ORG link : CVE-2026-83991

JSON object : View

Products Affected

microsoft

windows_11_26h1
windows_11_25h2
windows_10_21h2
windows_server_2019
windows_11_23h2
windows_10_22h2
windows_server_2022
windows_11_24h2
windows_server_2025
windows_10_1809

CWE

CWE-306

Missing Authentication for Critical Function

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"lessThan": "10.0.22631.7582", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 Version 24H2", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.9445", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 Version 25H2", "versions": [{"status": "affected", "version": "10.0.26200.0", "lessThan": "10.0.26200.9445", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows 11 version 26H1", "versions": [{"status": "affected", "version": "10.0.28000.0", "lessThan": "10.0.28000.2954", "versionType": "custom"}], "platforms": ["ARM64-based Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2019", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9245", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2019 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.9245", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2022", "versions": [{"status": "affected", "version": "10.0.20348.0", "lessThan": "10.0.20348.5622", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33438", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Windows Server 2025 (Server Core installation)", "versions": [{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.33438", "versionType": "custom"}], "platforms": ["x64-based Systems"]}]}], "published": 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