CVE-2026-50349: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Published Sep 8, 2026
·Updated
Concurrent execution using shared resource with improper synchronization ('race condition') 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
54 affected componentsFixes available
Microsoft Windows Server 2012 R2<6.3.9600.23397
6.3.9600.23397
Microsoft Windows Server 2012<6.2.9200.26349
6.2.9200.26349
Microsoft Windows Server 2012<6.2.9200.26349
6.2.9200.26349
Microsoft Windows 10=1607
10.0.14393.9512
Microsoft Windows Server 2016<10.0.14393.9512
10.0.14393.9512
Microsoft Windows Server 2012 R2<6.3.9600.23397
6.3.9600.23397
Microsoft Windows 10=1607
10.0.14393.9512
Microsoft Windows 11=26H1
10.0.28000.2954
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows Server 2016<10.0.14393.9512
10.0.14393.9512
Microsoft Windows 11=26H1
10.0.28000.2954
Microsoft Windows 11=23H2
10.0.22631.7582
Microsoft Windows 11=23H2
10.0.22631.7582
Microsoft Windows 11=24H2
10.0.26100.9445
Microsoft Windows 11=25H2
10.0.26200.9445
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows 11=25H2
10.0.26200.9445
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows 11=24H2
10.0.26100.9445
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows 10=22H2
10.0.19045.7725
Microsoft Windows Server 2025<10.0.26100.33438
10.0.26100.33438
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows 10=21H2
10.0.19044.7725
Microsoft Windows Server 2022<10.0.20348.5622
10.0.20348.5622
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows 10=1809
10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows Server 2019<10.0.17763.9245
10.0.17763.9245
Microsoft Windows 10 1607<10.0.14393.9512
Microsoft Windows 10 1607<10.0.14393.9512
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows 10 1809<10.0.17763.9245
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 21h2<10.0.19044.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 10 22h2<10.0.19045.7725
Microsoft Windows 11 23h2<10.0.22631.7582
Microsoft Windows 11 23h2<10.0.22631.7582
Microsoft Windows 11 24h2<10.0.26100.9445
Microsoft Windows 11 24h2<10.0.26100.9445
Microsoft Windows 11 25h2<10.0.26200.9445
Microsoft Windows 11 25h2<10.0.26200.9445
Microsoft Windows 11 26h1<10.0.28000.2954
Microsoft Windows 11 26h1<10.0.28000.2954
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016<10.0.14393.9512
Microsoft Windows Server 2019<10.0.17763.9245
Microsoft Windows Server 2022<10.0.20348.5622
Microsoft Windows Server 2025<10.0.26100.33438
Remediation
Event History
Sep 8, 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·05:10 PM
Data Sourced
via MITRE·05:10 PM
DescriptionSeverity
Data Sourced
via NVD·06:17 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
Who can exploit this vulnerability?
An attacker must already be authorized on the affected system and able to execute code locally. The provided data does not indicate that it is remotely exploitable or requires user interaction.
2
Which systems are listed as affected?
The affected software list includes Microsoft Windows 10, Windows 11, and Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025.
3
What is the likely impact if exploitation succeeds?
Successful exploitation allows local elevation of privilege. The supplied vector also rates confidentiality, integrity, and availability impact as high.