CVE-2026-68820MicrosoftOperating systemsAugust 11, 2026

Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

High 7Actively exploited

Description

Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.

What to do

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.

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Details

Vendor
Microsoft
Product
Windows
CVE
CVE-2026-68820
Affected versions
Windows 10 Version 1607 10.0: from 10.0.14393.0 to 10.0.14393.9418 (excluded) — fixed in 10.0.14393.9418
Windows 10 Version 1809 10.0: from 10.0.17763.0 to 10.0.17763.9121 (excluded) — fixed in 10.0.17763.9121
Windows 10 Version 21H2 10.0: from 10.0.19044.0 to 10.0.19044.7663 (excluded) — fixed in 10.0.19044.7663
Windows 10 Version 22H2 10.0: from 10.0.19045.0 to 10.0.19045.7663 (excluded) — fixed in 10.0.19045.7663
Windows 11 version 23H2 10.0: from 10.0.22631.0 to 10.0.22631.7517 (excluded) — fixed in 10.0.22631.7517
Windows 11 Version 23H2 10.0: from 10.0.22631.0 to 10.0.22631.7517 (excluded) — fixed in 10.0.22631.7517
Windows 11 Version 24H2 10.0: from 10.0.26100.0 to 10.0.26100.9168 (excluded) — fixed in 10.0.26100.9168
Windows 11 Version 25H2 10.0: from 10.0.26200.0 to 10.0.26200.9168 (excluded) — fixed in 10.0.26200.9168
Windows 11 version 26H1 10.0: from 10.0.28000.0 to 10.0.28000.2704 (excluded) — fixed in 10.0.28000.2704
Windows Server 2012 6.2: from 6.2.9200.0 to 6.2.9200.26280 (excluded) — fixed in 6.2.9200.26280
Windows Server 2012 (Server Core installation) 6.2: from 6.2.9200.0 to 6.2.9200.26280 (excluded) — fixed in 6.2.9200.26280
Windows Server 2012 R2 6.3: from 6.3.9600.0 to 6.3.9600.23338 (excluded) — fixed in 6.3.9600.23338
Windows Server 2012 R2 (Server Core installation) 6.3: from 6.3.9600.0 to 6.3.9600.23338 (excluded) — fixed in 6.3.9600.23338
Windows Server 2016 10.0: from 10.0.14393.0 to 10.0.14393.9418 (excluded) — fixed in 10.0.14393.9418
Windows Server 2016 (Server Core installation) 10.0: from 10.0.14393.0 to 10.0.14393.9418 (excluded) — fixed in 10.0.14393.9418
Windows Server 2019 10.0: from 10.0.17763.0 to 10.0.17763.9121 (excluded) — fixed in 10.0.17763.9121
Windows Server 2019 (Server Core installation) 10.0: from 10.0.17763.0 to 10.0.17763.9121 (excluded) — fixed in 10.0.17763.9121
Windows Server 2022 10.0: from 10.0.20348.0 to 10.0.20348.5499 (excluded) — fixed in 10.0.20348.5499
Windows Server 2025 10.0: from 10.0.26100.0 to 10.0.26100.33296 (excluded) — fixed in 10.0.26100.33296
Windows Server 2025 (Server Core installation) 10.0: from 10.0.26100.0 to 10.0.26100.33296 (excluded) — fixed in 10.0.26100.33296 (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
7
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
August 25, 2026 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
August 11, 2026

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

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