CVE-2026-68820
Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-08-11. Federal due date: 2026-08-25.
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Impact
Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Windows 11 Version 24H2 | from 10.0.26100.0 before 10.0.26100.9168 |
| Microsoft | Windows Server 2022 | from 10.0.20348.0 before 10.0.20348.5499 |
| Microsoft | Windows Server 2012 R2 | from 6.3.9600.0 before 6.3.9600.23338 |
| Microsoft | Windows 10 Version 22H2 | from 10.0.19045.0 before 10.0.19045.7663 |
| Microsoft | Windows Server 2012 | from 6.2.9200.0 before 6.2.9200.26280 |
| Microsoft | Windows Server 2025 (Server Core Installation) | from 10.0.26100.0 before 10.0.26100.33296 |
| Microsoft | Windows 10 Version 21H2 | from 10.0.19044.0 before 10.0.19044.7663 |
| Microsoft | Windows Server 2016 (Server Core Installation) | from 10.0.14393.0 before 10.0.14393.9418 |
| Microsoft | Windows Server 2019 (Server Core Installation) | from 10.0.17763.0 before 10.0.17763.9121 |
| Microsoft | Windows 11 Version 25H2 | from 10.0.26200.0 before 10.0.26200.9168 |
| Microsoft | Windows Server 2016 | from 10.0.14393.0 before 10.0.14393.9418 |
| Microsoft | Windows Server 2019 | from 10.0.17763.0 before 10.0.17763.9121 |
| Microsoft | Windows 10 1607 | before 10.0.14393.9418 |
| Microsoft | Windows 10 1809 | before 10.0.17763.9115 |
| Microsoft | Windows 10 21h2 | before 10.0.19044.7663 |
| Microsoft | Windows 10 22h2 | before 10.0.19045.7663 |
| Microsoft | Windows 11 23h2 | before 10.0.22631.7517 |
| Microsoft | Windows 11 24h2 | before 10.0.26100.9106 |
| Microsoft | Windows 11 25h2 | before 10.0.26200.9106 |
| Microsoft | Windows 11 26h1 | before 10.0.28000.2704 |
| Microsoft | Windows Server 2012 | All versions Version r2 |
| Microsoft | Windows Server 2016 | before 10.0.14393.9418 |
| Microsoft | Windows Server 2019 | before 10.0.17763.9115 |
| Microsoft | Windows Server 2022 | before 10.0.20348.5440 |