The 31-year-old noticed something was strange when she looked for her "mum" in her contacts and was surprised to see four other "mums" had come up on her screen!
After further investigation, Highfield began typing other letters into her phone and found the contact numbers for Radio 1 DJs, Olympic athletes, and even superstar singers!
Contacts in her all-star phone book included gold medalist Greg Rutherford, comedian David Walliams, Nick Grimshaw (listed as Grimmy), Spice GirlEmma Bunton, and the one and only Adele!
The iPhone user has "no idea" how the celebrity numbers got in her phone, telling Digital Spy:
"I seem to have access to literally hundreds of people's numbers. I didn't notice it at first because the contacts aren't in my address book but when I go into messages to send a text and type in the letter 'A', it comes up with 'A' for Adele… There are also lots of producers. I feel like it might have belonged to someone from the BBC or the TV industry."
While most people would be excited to have Adele's personal line, Highfield said it was "quite annoying" to have hundreds of numbers suddenly appear on her phone. She added:
"I feel like it is a data breach. I've not been entirely sure what to do. It's kind of a big thing. I haven't purchased these numbers, they've just fallen into my hands."
While not even Apple quite knows what went wrong, experts say it could likely be an "iCloud glitch" that made her 5S sync with dozens of others.
Well, at least these numbers were glitched into the right hands — because we're sure less honorable iPhone users would have had a lot of fun dialing Adele just to say Hello.
News is just coming in that Kim Zolciak-Biermann's son Kash, 4, was bitten by a dog at some point on Saturday night, with "traumatic injuries" so extensive, it required multiple hours of surgery afterwards.