Junglewise Threat Intelligence

CVE-2026-45601: Microsoft Windows use after free in Ancillary Function Driver for WinSock

CVE-2026-45601 · Severity: high · CVSS 7 · Published 2026-06-09

Technologies: Microsoft Windows. Vendors: Microsoft.

Executive brief

A security vulnerability exists in a core Windows networking component that handles socket connections. An attacker who already has basic access to a computer could exploit this flaw to gain full administrative control over the system. This could allow them to bypass security restrictions, access sensitive data, or install malicious software.

Technical details

A use-after-free vulnerability exists in the Windows Ancillary Function Driver (afd.sys) for WinSock. The flaw is rooted in a race condition (CWE-362) during concurrent execution using shared resources with improper synchronization. To exploit this, an attacker must first have local access to the system with low-level privileges. Successful exploitation allows the attacker to execute code with SYSTEM privileges, leading to a complete compromise of the host's confidentiality, integrity, and availability.

Affected products

  • Microsoft Windows

Timeline

  • 2026-06-09: disclosed
  • 2026-06-09: advisory

References