CVE-2026-83991

medium

Description

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

References

https://github.com/ZeroDayVPN/CVE-2026-83991-WriteUP-and-PoC

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83991

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-73359

Details

Source: Mitre, NVD

Published: 2026-09-08

Updated: 2026-09-09

Risk Information

CVSS v2

Base Score: 4.6

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Severity: Medium

EPSS

EPSS: 0.00349