CVE-2026-61939: Winlogon Elevation of Privilege Vulnerability

Published Aug 11, 2026
·
Updated

Use after free in Winlogon allows an authorized attacker to elevate privileges locally.

Other sources

Winlogon Elevation of Privilege Vulnerability

— Microsoft

Affected Software

30 affected componentsFixes available
Microsoft Windows Server 2012 R2<6.3.9600.23337
6.3.9600.23337
Microsoft Windows 10=1607
10.0.14393.9418
Microsoft Windows Server 2025<10.0.26100.33296, <10.0.26100.33222
10.0.26100.3329610.0.26100.33222
Microsoft Windows 11=26H1
10.0.28000.2704
Microsoft Windows 11=26H1
10.0.28000.2704
Microsoft Windows Server 2016<10.0.14393.9418
10.0.14393.9418
Microsoft Windows 10=1607
10.0.14393.9418
Microsoft Windows Server 2016<10.0.14393.9418
10.0.14393.9418
Microsoft Windows 11=24H2
10.0.26100.916810.0.26100.9106
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows 11=24H2
10.0.26100.916810.0.26000.9106
Microsoft Windows 11=25H2
10.0.26200.916810.0.26100.9106
Microsoft Windows Server 2012 R2<6.3.9600.23337
6.3.9600.23337
Microsoft Windows 11=25H2
10.0.26200.916810.0.26100.9106
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows Server 2012<6.2.9200.26279
6.2.9200.26279
Microsoft Windows 10=21H2
10.0.19044.7663
Microsoft Windows 10=22H2
10.0.19045.7663
Microsoft Windows 10=21H2
10.0.19044.7663
Microsoft Windows Server 2025<10.0.26100.33296, <10.0.26100.33222
10.0.26100.3329610.0.26100.33222
Microsoft Windows 10=21H2
10.0.19044.7663
Microsoft Windows 10=22H2
10.0.19045.7663
Microsoft Windows Server 2022<10.0.20348.5499, <10.0.20348.5440
10.0.20348.549910.0.20348.5440
Microsoft Windows 10=22H2
10.0.19045.7663
Microsoft Windows 10=1809
10.0.17763.9115
Microsoft Windows Server 2022<10.0.20348.5499, <10.0.20348.5440
10.0.20348.549910.0.20348.5440
Microsoft Windows Server 2019<10.0.17763.9115
10.0.17763.9115
Microsoft Windows Server 2019<10.0.17763.9115
10.0.17763.9115
Microsoft Windows Server 2012<6.2.9200.26279
6.2.9200.26279
Microsoft Windows 10=1809
10.0.17763.9115

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 6.3.9600.23337Patch KB5120386
  2. Upgrade

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

    Fixed in 10.0.14393.9418Patch KB5120418
  3. Upgrade

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

    Fixed in 10.0.28000.2704Patch KB5121000
  4. Upgrade

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

    Fixed in 10.0.26100.33296Fixed in 10.0.26100.33222Patch KB5120228
  5. Upgrade

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

    Fixed in 10.0.26100.9168Fixed in 10.0.26100.9106Patch KB5120994
  6. Upgrade

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

    Fixed in 10.0.22631.7517Patch KB5120240
  7. Upgrade

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

    Fixed in 10.0.26100.9168Fixed in 10.0.26000.9106Patch KB5120994
  8. Upgrade

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

    Fixed in 10.0.26200.9168Fixed in 10.0.26100.9106Patch KB5120994
  9. Upgrade

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

    Fixed in 6.2.9200.26279Patch KB5120385
  10. Upgrade

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

    Fixed in 10.0.19045.7663Patch KB5120249
  11. Upgrade

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

    Fixed in 10.0.19044.7663Patch KB5120249
  12. Upgrade

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

    Fixed in 10.0.20348.5499Fixed in 10.0.20348.5440Patch KB5120229
  13. Upgrade

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

    Fixed in 10.0.17763.9115Patch KB5120238

Event History

Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:18 PM
DescriptionSeverityWeakness
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-2026-61939?

CVE-2026-61939 has a severity rating of high with a score of 7.

2

What type of vulnerability is CVE-2026-61939?

CVE-2026-61939 is a use after free vulnerability in Winlogon.

3

Which software is affected by CVE-2026-61939?

CVE-2026-61939 affects Microsoft Windows 10, Windows 11, and various versions of Windows Server.

4

How can an attacker exploit CVE-2026-61939?

An authorized attacker can exploit CVE-2026-61939 to elevate privileges locally on the affected system.

5

What is the impact of CVE-2026-61939?

CVE-2026-61939 allows unauthorized privilege escalation, potentially compromising system security.

Company

Resources

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