WinFsp

WinFsp Vulnerability CVE-2026-3006 Allows Local Attackers to Escalate Privileges to SYSTEM via Race Condition in Kernel Driver

A critical vulnerability has been discovered in WinFsp, the open-source platform used to implement virtual disks, network file shares, and custom file systems on Windows. The flaw, tracked as CVE-2026-3006 with a CVSS 3.1 score of 7.0, affects version 2.1.25156 and all earlier releases, enabling a local attacker to trigger a race condition that leads to a memory overflow inside the kernel-mode driver. Successful exploitation grants full SYSTEM-level privileges, allowing modification of protected files, installation of services and drivers, disabling of security mechanisms, and creation of new accounts. The issue cannot be exploited remotely and requires the attacker to already have the ability to execute code on the target system, either through a compromised account or by running malicious software. WinFsp components are frequently bundled inside third-party virtualization and storage applications, significantly expanding the potential attack surface. Developers have released a fix in WinFsp 2.2B1, while Singapore’s Cyber Security Agency recommends immediate updates, restriction of local administrative rights, and monitoring for unexpected driver or service changes.