CVE-2026-61936: Windows Defender Firewall Service Security Feature Bypass Vulnerability

Published Aug 11, 2026
·
Updated

Missing authorization in Windows Defender Firewall Service allows an authorized attacker to bypass a security feature locally.

Other sources

Windows Defender Firewall Service Security Feature Bypass Vulnerability

— Microsoft

Affected Software

41 affected componentsFixes available
Microsoft Windows Server 2019<10.0.17763.9115
10.0.17763.9115
Microsoft Windows 10=1809
10.0.17763.9115
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 10=1809
10.0.17763.9115
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows 11=26H1
10.0.28000.2704
Microsoft Windows 10=22H2
10.0.19045.7663
Microsoft Windows 11=23H2
10.0.22631.7517
Microsoft Windows 10=22H2
10.0.19045.7663
Microsoft Windows 10=21H2
10.0.19044.7663
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=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 Server 2019<10.0.17763.9115
10.0.17763.9115
Microsoft Windows 10=21H2
10.0.19044.7663
Microsoft Windows Server 2022<10.0.20348.5499, <10.0.20348.5440
10.0.20348.549910.0.20348.5440
Microsoft Windows 10 1809<10.0.17763.9115
Microsoft Windows 10 1809<10.0.17763.9115
Microsoft Windows 10 21h2<10.0.19044.7663
Microsoft Windows 10 21h2<10.0.19044.7663
Microsoft Windows 10 21h2<10.0.19044.7663
Microsoft Windows 10 22h2<10.0.19045.7663
Microsoft Windows 10 22h2<10.0.19045.7663
Microsoft Windows 10 22h2<10.0.19045.7663
Microsoft Windows 11 23h2<10.0.22631.7517
Microsoft Windows 11 23h2<10.0.22631.7517
Microsoft Windows 11 24h2<10.0.26100.9106
Microsoft Windows 11 24h2<10.0.26100.9106
Microsoft Windows 11 25h2<10.0.26200.9106
Microsoft Windows 11 25h2<10.0.26200.9106
Microsoft Windows 11 26h1<10.0.28000.2704
Microsoft Windows 11 26h1<10.0.28000.2704
Microsoft Windows Server 2019<10.0.17763.9115
Microsoft Windows Server 2022<10.0.20348.5440
Microsoft Windows Server 2025<10.0.26100.33222
Microsoft Windows 11=24H2
10.0.26100.916810.0.26200.9106
Microsoft Windows 11=24H2
10.0.26100.916810.0.26100.9106
Microsoft Windows 11=25H2
10.0.26200.916810.0.26200.9106
Microsoft Windows 11=25H2
10.0.26200.916810.0.26200.9106

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 10.0.17763.9115Patch KB5120238
  2. 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
  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 10.0.22631.7517Patch KB5120240
  5. Upgrade

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

    Fixed in 10.0.19045.7663Patch KB5120249
  6. Upgrade

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

    Fixed in 10.0.19044.7663Patch KB5120249
  7. 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
  8. Upgrade

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

    Fixed in 10.0.26100.9168Fixed in 10.0.26200.9106Patch KB5120994
  9. 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
  10. Upgrade

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

    Fixed in 10.0.26200.9168Fixed in 10.0.26200.9106Patch KB5120994

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
RemedyDescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-61936?

The severity of CVE-2026-61936 is rated as medium with a score of 5.5.

2

How do I fix CVE-2026-61936?

To fix CVE-2026-61936, ensure that all relevant security updates and patches are applied to your Windows operating system.

3

Which systems are affected by CVE-2026-61936?

CVE-2026-61936 affects Microsoft Windows 10, Windows 11, Windows Server 2019, 2022, and 2025.

4

What type of vulnerability is CVE-2026-61936?

CVE-2026-61936 is a security feature bypass vulnerability found in the Windows Defender Firewall Service.

5

Can an attacker exploit CVE-2026-61936 remotely?

CVE-2026-61936 requires local access, meaning that an attacker must be authorized and physically present to exploit this vulnerability.

Company

Resources

Contact

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