CVE-2026-83991
Windows Cloud Files Mini Filter Driver Tampering Vulnerability
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Windows Cloud Files Mini Filter Driver Tampering Vulnerability
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
- Record
CVE-2026-83991- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C - Weakness
- CWE-306
- Updated
- 2026-11-10
EUVDEUVD-2026-73359
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
- Record
EUVD-2026-73359- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C - Updated
- 2026-11-10
GitHub AdvisoriesGHSA-6xxg-24pf-j6jx
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an...
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
- Record
GHSA-6xxg-24pf-j6jx- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
Missing authentication for critical function in Windows Cloud Files Mini Filter Driver allows an authorized attacker to perform tampering locally.
- Record
CVE-2026-83991- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
Affected products
- microsoft windows 10 version 1809
- microsoft windows 10 version 21h2
- microsoft windows 10 version 22h2
- microsoft windows 11 version 23h2
- microsoft windows 11 version 24h2
- microsoft windows 11 version 25h2
- microsoft windows 11 version 26h1
- microsoft windows server 2019
- microsoft windows server 2019 (server core installation)
- microsoft windows server 2022
- microsoft windows server 2025
- microsoft windows server 2025 (server core installation)
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | karollooool/CVE-2026-83991-writeup-and-poc | 2026-09-09 |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploits, facts | PoC in GitHub | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-83991 is a medium vulnerability (CVSS 5.5) in Microsoft Windows 10 Version 1809, published September 8, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.30%, the 23rd percentile. No source names a fixed version.