https://techcrunch.com/2017/10/06/apple-is-looking-into-reports-of-iphone-8-batteries-swelling/

Reports from a few iPhone 8 and iPhone 8 Plus buyers have suggested there could be an issue with the battery inside some of the devices swelling, causing the case of Apple’s new iPhone to split open and expose the smartphone’s internals.

Apple has now confirmed it is looking into it, although a spokeswoman declined to comment further when asked how many devices are affected.