Windows Hello face unlock now doesn’t work in the dark by default

If you have been relying on Windows Hello facial unlock to access your Windows 11 PC, you may have noticed that it no longer functions in the dark. This is a result of the Windows 11 update OS Build 26100.3775, which was released in April.

The update means that Windows 11 users can no longer unlock their PCs in low-light conditions unless their device has a webcam that supports colour cameras to see a visible face during sign-in. Here are the details.

Microsoft Windows Hello: Low-Light Unlocking No Longer Works But What’s The Alternate?

As spotted by Windows Central, Microsoft now requires better security protocols to improve Windows Hello. In the Windows change log, Microsoft stated that post this update, or a later one, Windows now needs colour cameras to power Windows Hello.

“After installing this update or a later Windows update, for enhanced security, Windows Hello facial recognition requires color cameras to see a visible face when signing in.”

This change has been introduced to fix a vulnerability, specifically CVE-2025-26644, which allowed for Windows Hello spoofing. With this update, the technology company has addressed the issue. The vulnerability summary describes it as an "Automated recognition mechanism with inadequate detection or handling of adversarial input perturbations in Windows Hello allows an unauthorized attacker to perform spoofing locally.”

How Did Windows Hello Work Previously?

Previously, for those unfamiliar with the system, Windows Hello relied solely on infrared sensors to detect a 3D scan of your face, similar to how Apple's Face ID works.

In terms of real-world changes, you will now need to be in a well-lit environment to use facial unlock. This may involve increasing your screen's brightness to illuminate your face or simply switching on a light if you are in a dark room.

MOBILE FINDER: iPhone 16 LATEST Price, Specs And More