CVE-2026-45596: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Published Jun 9, 2026
·
Updated

Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Other sources

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Microsoft

Affected Software

55 affected componentsFixes available
Microsoft Windows Ancillary Function Driver for WinSock
Microsoft Windows 10 1607<10.0.14393.9234
Microsoft Windows 10 1607<10.0.14393.9234
Microsoft Windows 10 1809<10.0.17763.8880
Microsoft Windows 10 1809<10.0.17763.8880
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 21h2<10.0.19044.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 10 22h2<10.0.19045.7417
Microsoft Windows 11 23h2<10.0.22631.7219
Microsoft Windows 11 23h2<10.0.22631.7219
Microsoft Windows 11 24h2<10.0.26100.8655
Microsoft Windows 11 24h2<10.0.26100.8655
Microsoft Windows 11 25h2<10.0.26200.8655
Microsoft Windows 11 25h2<10.0.26200.8655
Microsoft Windows 11 26h1<10.0.28000.2269
Microsoft Windows 11 26h1<10.0.28000.2269
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016<10.0.14393.9234
Microsoft Windows Server 2019<10.0.17763.8880
Microsoft Windows Server 2022<10.0.20348.5256
Microsoft Windows Server 2025<10.0.26100.32995
Microsoft Windows 11=26H1
10.0.28000.2269
Microsoft Windows Server 2012<6.2.9200.26132
6.2.9200.26132
Microsoft Windows 10=1607
10.0.14393.9234
Microsoft Windows Server 2025<10.0.26100.32995
10.0.26100.32995
Microsoft Windows Server 2016<10.0.14393.9234
10.0.14393.9234
Microsoft Windows Server 2012 R2<6.3.9600.23228
6.3.9600.23228
Microsoft Windows Server 2016<10.0.14393.9234
10.0.14393.9234
Microsoft Windows Server 2012<6.2.9200.26132
6.2.9200.26132
Microsoft Windows 10=1607
10.0.14393.9234
Microsoft Windows Server 2012 R2<6.3.9600.23228
6.3.9600.23228
Microsoft Windows 11=26H1
10.0.28000.2269
Microsoft Windows 11=25H2
10.0.26200.8655
Microsoft Windows Server 2025<10.0.26100.32995
10.0.26100.32995
Microsoft Windows 11=23H2
10.0.22631.7219
Microsoft Windows 11=24H2
10.0.26100.8655
Microsoft Windows 10=22H2
10.0.19045.7417
Microsoft Windows 11=24H2
10.0.26100.8655
Microsoft Windows 11=23H2
10.0.22631.7219
Microsoft Windows 11=25H2
10.0.26200.8655
Microsoft Windows 10=22H2
10.0.19045.7417
Microsoft Windows Server 2019<10.0.17763.8880
10.0.17763.8880
Microsoft Windows 10=22H2
10.0.19045.7417
Microsoft Windows Server 2022<10.0.20348.5256
10.0.20348.5256
Microsoft Windows 10=21H2
10.0.19044.7417
Microsoft Windows 10=21H2
10.0.19044.7417
Microsoft Windows 10=21H2
10.0.19044.7417
Microsoft Windows Server 2022<10.0.20348.5256
10.0.20348.5256
Microsoft Windows Server 2019<10.0.17763.8880
10.0.17763.8880
Microsoft Windows 10=1809
10.0.17763.8880
Microsoft Windows 10=1809
10.0.17763.8880

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 10.0.28000.2269Patch KB5095051
  2. Upgrade

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

    Fixed in 6.2.9200.26132Patch KB5094042
  3. Upgrade

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

    Fixed in 10.0.14393.9234Patch KB5094122
  4. Upgrade

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

    Fixed in 10.0.26100.32995Patch KB5094125
  5. Upgrade

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

    Fixed in 6.3.9600.23228Patch KB5094041
  6. Upgrade

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

    Fixed in 10.0.26200.8655Patch KB5094126
  7. Upgrade

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

    Fixed in 10.0.22631.7219Patch KB5093998
  8. Upgrade

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

    Fixed in 10.0.26100.8655Patch KB5094126
  9. Upgrade

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

    Fixed in 10.0.19045.7417Patch KB5094127
  10. Upgrade

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

    Fixed in 10.0.17763.8880Patch KB5094123
  11. Upgrade

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

    Fixed in 10.0.20348.5256Patch KB5094128
  12. Upgrade

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

    Fixed in 10.0.19044.7417Patch KB5094127

Event History

Jun 9, 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
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:05 PM
Data Sourced
via MITRE·05:05 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-45596?

CVE-2026-45596 has a severity rating of high, with a score of 7.

2

How can I mitigate CVE-2026-45596?

To mitigate CVE-2026-45596, ensure that your Windows operating system is updated with the latest security patches from Microsoft.

3

What systems are affected by CVE-2026-45596?

CVE-2026-45596 affects Microsoft Windows 10, Windows 11, and several versions of Windows Server including 2012, 2016, 2019, 2022, and 2025.

4

What type of vulnerability is CVE-2026-45596?

CVE-2026-45596 is classified as an elevation of privilege vulnerability due to a use after free condition.

5

Who can exploit CVE-2026-45596?

CVE-2026-45596 can be exploited by an authorized attacker who has local access to the affected system.

Contact

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