CVE-2026-20940: Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability

Published Jan 13, 2026
·
Updated

Heap-based buffer overflow in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.

Other sources

Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability

Microsoft

Affected Software

48 affected componentsFixes available
Microsoft Windows 10 1607<10.0.14393.8783
Microsoft Windows 10 1607<10.0.14393.8783
Microsoft Windows 10 1809<10.0.17763.8276
Microsoft Windows 10 1809<10.0.17763.8276
Microsoft Windows 10 21h2<10.0.19044.6809
Microsoft Windows 10 21h2<10.0.19044.6809
Microsoft Windows 10 21h2<10.0.19044.6809
Microsoft Windows 10 22h2<10.0.19045.6809
Microsoft Windows 10 22h2<10.0.19045.6809
Microsoft Windows 10 22h2<10.0.19045.6809
Microsoft Windows 11 23h2<10.0.22631.6491
Microsoft Windows 11 23h2<10.0.22631.6491
Microsoft Windows Server 2008=sp2
Microsoft Windows Server 2008=sp2
Microsoft Windows Server 2008=r2-sp1
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016<10.0.14393.8783
Microsoft Windows Server 2019<10.0.17763.8276
Microsoft Windows Server 2022<10.0.20348.4648
Microsoft Windows Server 2022<10.0.20348.4648
10.0.20348.4648
Microsoft Windows 10=1809
10.0.17763.8276
Microsoft Windows 10=1809
10.0.17763.8276
Microsoft Windows Server 2022<10.0.20348.4648
10.0.20348.4648
Microsoft Windows Server 2012<6.2.9200.25868
6.2.9200.25868
Microsoft Windows Server 2012 R2<6.3.9600.22968
6.3.9600.22968
Microsoft Windows Server 2008 R2<6.1.7601.28117
6.1.7601.28117
Microsoft Windows Server 2012<6.2.9200.25868
6.2.9200.25868
Microsoft Windows Server 2019<10.0.17763.8276
10.0.17763.8276
Microsoft Windows 10=21H2
10.0.19044.6809
Microsoft Windows Server 2012 R2<6.3.9600.22968
6.3.9600.22968
Microsoft Windows 10=21H2
10.0.19044.6809
Microsoft Windows 10=1607
10.0.14393.8783
Microsoft Windows Server 2008<6.0.6003.23717
6.0.6003.23717
Microsoft Windows Server 2016<10.0.14393.8783
10.0.14393.8783
Microsoft Windows 10=22H2
10.0.19045.6809
Microsoft Windows Server 2008<6.0.6003.23717
6.0.6003.23717
Microsoft Windows Server 2008 R2<6.1.7601.28117
6.1.7601.28117
Microsoft Windows Server 2008<6.0.6003.23717
6.0.6003.23717
Microsoft Windows Server 2016<10.0.14393.8783
10.0.14393.8783
Microsoft Windows 10=1607
10.0.14393.8783
Microsoft Windows 10=22H2
10.0.19045.6809
Microsoft Windows Server 2008<6.0.6003.23717
6.0.6003.23717
Microsoft Windows 11=23H2
10.0.22631.6491
Microsoft Windows 10=21H2
10.0.19044.6809
Microsoft Windows 11=23H2
10.0.22631.6491
Microsoft Windows Server 2019<10.0.17763.8276
10.0.17763.8276
Microsoft Windows 10=22H2
10.0.19045.6809

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.20348.4648Patch KB5073457
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.17763.8276Patch KB5073723
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.2.9200.25868Patch KB5073698
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.3.9600.22968Patch KB5073696
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.1.7601.28117Patch KB5073699
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19044.6809Patch KB5073724
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.14393.8783Patch KB5073722
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.0.6003.23717Patch KB5073700
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.19045.6809Patch KB5073724
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.22631.6491Patch KB5073455

Event History

Jan 13, 2026
CVE Published
via Microsoft·04:00 PM
Data Sourced
via Microsoft·04:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·04:00 PM
Affected Software
Updated
via Microsoft·04:00 PM
Description
CVE Published
via MITRE·05:56 PM
Data Sourced
via MITRE·05:56 PM
DescriptionSeverity
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeaknessAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-20940?

CVE-2026-20940 is classified as an elevation of privilege vulnerability with high severity.

2

How do I fix CVE-2026-20940?

To fix CVE-2026-20940, apply the security updates released by Microsoft for your affected Windows version.

3

What systems are affected by CVE-2026-20940?

CVE-2026-20940 affects various versions of Microsoft Windows, including Windows 10, Windows Server 2019, and Windows Server 2022.

4

Can CVE-2026-20940 be exploited remotely?

CVE-2026-20940 requires local access to exploit, as it is an elevation of privilege vulnerability.

5

What is the potential impact of CVE-2026-20940?

The potential impact of CVE-2026-20940 is the ability for an authorized attacker to elevate their privileges on the affected system.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203