Executive brief
A security vulnerability exists in a core Windows networking component responsible for handling 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 view sensitive data, install malicious software, or disrupt business operations.
Technical details
A privilege escalation vulnerability exists in the Windows Ancillary Function Driver (afd.sys) for WinSock due to improper validation of file names or paths (CWE-73). An attacker with low-privileged local access can exploit this by providing a specially crafted path to the driver, leading to execution with SYSTEM privileges. The vulnerability is reachable via local attack vectors and does not require user interaction. Microsoft has released security updates to address this issue across affected Windows and Windows Server versions.
Affected products
- Microsoft Windows 10 Versions 1607, 1809, 21H2, 22H2
- Microsoft Windows 11 Versions 24H2, 25H2, 26H1
- Microsoft Windows Server 2012 All editions including Server Core
Timeline
- 2026-07-14: disclosed
- 2026-07-14: advisory