This is why your iPhone deleted photos are back

The release of iOS 17.5 brought with it a slightly disturbing bug, as many users reported that old, deleted photos had reappeared, some from more than a decade after they were deleted. Although Apple has fixed this bug in iOS 17.5.1, many people are still wondering what exactly caused the problem.

While there are rumors that this may be related to issues with iCloud photo backup itself, Apple has confirmed to 9to5Mac that the issue does not originate from iCloud. Instead, the tech company says the redisplay of photos is caused by corrupted database entries present on the affected phones' file systems.

But how does it work, especially since many of us no longer use the same devices we did more than five years ago? Apple says the issue may have been transferred to newer devices via a device-to-device transfer, restoring from an iCloud backup, or restoring from a backup on the device itself.

To better understand the issue and its workaround, security researchers at Synactiv took a deeper look at the issue by reverse-engineering the iOS 17.5.1 update to understand what has changed. According to their report, iOS 17.5 appears to have added a migration routine that scans and re-imports photos from the file system. Apple removed this routine in the iOS 17.5.1 update as it appeared to be the reason why old files were re-indexed on the local file system and moved back to the active Photos Library.

Synactiv told The Verge that the photos appear to have been present on the affected file system and "according to the code," they were picked up by a migration routine. Unfortunately, security researchers say there's really no way to tell how the photo ended up on the file system in the first place.

However, another possible cause pointed out by Synactiv is a Reddit comment stating that sometimes your device saves files to the Files app and Photos app. So if you just delete an image in the Photos app, the image will still be on your device and stored in Files.

Unfortunately, there's no way to determine whether the issue is down to the image being saved in two places or Apple's "corrupt database entry" explanation. Now, as long as you update to iOS 17.5.1, the problem is solved. If you're one of the few people who has old photos resurfaced, you'll need to delete them yourself as the update won't delete them automatically.