VulnerabilityAnalyzed
CVE-2026-83991
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
MEDIUM 5.5EPSS 0.34%
Does this matter?
Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.
Description
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.34% probability · 27th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-306
- Affected
- microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows 11 25h2 · microsoft/windows 11 26h1 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2025
- Source
- secure@microsoft.com
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83991Vendor Advisory, Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.