A high-severity use after free vulnerability in Microsoft Windows 11 allows local authenticated attackers to achieve full privilege escalation.

This vulnerability is a use after free flaw within the Windows Hello component. It permits an attacker who has already gained low-level access to the system to manipulate memory and elevate their privileges to a higher level.

Successful exploitation of this vulnerability results in full privilege escalation, potentially granting an attacker administrative control over the compromised workstation. With a CVSS score of 8.8, this flaw poses a significant risk as it allows attackers to bypass security boundaries, potentially leading to unauthorized data access, persistence, and total system compromise.

Immediate Action: Apply the September 2026 security updates provided by Microsoft to the affected Windows 11 versions to patch the underlying memory management defect.

Proactive Monitoring: Monitor system logs for unusual process creation, unexpected privilege changes, or crashes related to the Windows Hello authentication service.

Compensating Controls: Ensure the principle of least privilege is strictly enforced to limit the number of users who can interact with sensitive authentication components.

Public Exploit Available: No

Given the severity of this privilege escalation flaw, administrators should prioritize the deployment of the vendor-supplied security patches across all affected Windows 11 endpoints. Failure to remediate could allow an attacker with limited access to seize complete control over the host system, undermining the entire security posture of the affected device.