Status
This vulnerability appears in CISA's catalog of known exploited vulnerabilities. It is not a theoretical risk — it is being used in the wild.
Description
Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.
Details
- Vendor: Microsoft
- Product: Windows Ancillary Function Driver for WinSock
- Added to catalog: 2026-08-11
Action Required by CISA
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.
- Due date for federal agencies: 2026-08-25
Microsoft
Windows Ancillary Function Driver for WinSock