CVE-2026-68820: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

Summary

A use-after-free vulnerability in the Microsoft Windows Ancillary Function Driver for WinSock allows local privilege escalation for authenticated attackers. CISA has mandated that federal agencies apply mitigations according to vendor instructions by August 25, 2026, following risk-based patching guidance.

IFF Assessment

FOE

This vulnerability allows an attacker to elevate privileges, posing a direct threat to system security.

Severity

7.0 High

CISA KEV: Listed as actively exploited. Federal patch due: August 25, 2026. Known ransomware use: Unknown.

Defender Context

This advisory highlights a critical privilege escalation vulnerability in a core Windows component, requiring immediate attention for patching and mitigation. Defenders should prioritize applying vendor-provided fixes and adhere to CISA's risk-based patching directives, especially for internet-facing systems.

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