Some Pixel 6a Phones Can Be Unlocked with Unregistered Fingerprints

Google’s new Pixel 6a smartphone has only just started shipping to those who pre-ordered, but some reviewers have noted a potentially serious bug. According to multiple reports, the latest Google phone can be unlocked with a fingerprint — any fingerprint, even if it’s not the one you registered or one that belongs to someone else entirely.

The Pixel 6a has an in-display fingerprint sensor, which is still a relatively new technology for Google. It first offered this feature on the Pixel 6 and 6 Pro, which launched in late 2021. There were no reports of this multi-fingerprint bug with those phones, but they were sluggish to unlock. The Pixel 6a, which uses a Goodix optical fingerprint sensor very similar to the Pixel 6, is much faster. Perhaps that’s part of the problem.

Optical fingerprint sensors are essentially high-contrast cameras that sit under the screen. Your device’s OLED panel lights up above the sensor to illuminate your fingerprint. The way it’s supposed to work, as you might expect, is that tapping the sensor with a registered finger unlocks the phone, but an unregistered print should be rejected. Several YouTubers and reviewers have now reported that their Pixels will unlock with unregistered fingerprints. One even showed it working with a fingerprint from someone else’s hand. This is a major security issue, but not a unique one.

Several years back, Samsung began using ultrasonic in-display fingerprint sensors. The Galaxy S10 mistakenly interpreted the patterns in some screen protectors as elements of the user’s fingerprint. Over time, the algorithm would get confused and allow anyone to unlock the phone because it could still see the screen protector patterns no matter who tapped. It’s hard to get this stuff right, and it appears Google still has some work to do.

That said, I’ve been testing a Pixel 6a for several weeks, and I have been unable to reproduce the error. The phone only unlocks with my registered fingerprints, and yes, it’s a bit faster than the Pixel 6 in that regard. I have no doubt Google will investigate the issue, and there will be an update that addresses the lax security. Whether or not that makes the Pixel 6a’s sensor as lethargic as the Pixel 6, only time will tell.

The Pixel 6a is still available for pre-order at the Google Store, where it can be yours in black, white, or green for $449. It’s unlocked for use on any carrier.