Windows Hello, Microsoft's biometric authentication system, has recently undergone a significant security enhancement that affects its functionality in low-light conditions. With the release of Windows 11 OS Build 26100.3775 in April 2025, users have observed that facial recognition no longer operates in the dark unless their device is equipped with a color camera capable of capturing visible light images during sign-in.
This change addresses a critical vulnerability, identified as CVE-2025-26644, which allowed unauthorized access through spoofing techniques. The vulnerability exploited the system's reliance on infrared (IR) sensors, enabling attackers to bypass authentication using manipulated IR images. By requiring color cameras, Windows Hello now ensures that facial recognition processes involve visible light imagery, significantly enhancing security measures.
Previously, Windows Hello depended solely on IR sensors to create a 3D map of a user's face, similar to Apple's Face ID. While effective under various lighting conditions, this method proved susceptible to sophisticated spoofing attacks. The updated requirement for color cameras mitigates this risk by incorporating an additional layer of verification, making unauthorized access more challenging.
Users with devices lacking color camera support may experience inconvenience due to this update, as facial recognition will not function in low-light environments. To maintain seamless access, affected users are advised to utilize alternative authentication methods, such as PINs or passwords, or consider upgrading their hardware to include compatible color cameras.
This proactive measure by Microsoft underscores the company's commitment to user security, even if it necessitates adjustments in user experience. By addressing potential vulnerabilities preemptively, Microsoft aims to provide a more secure computing environment for all Windows 11 users.
Source: Mint https://www.livemint.com/gadgets-and-appliances/windows-hello-face-unlock-now-doesn-t-work-in-the-dark-by-default-11750154553627.html
