Anyone who owns an iPhone must head to their settings and check for the latest iOS software without delay. Apple has just confirmed the release of an “important” update with the US technology firm, saying it is “recommended for all users.”

The release – which is called iOS 18.3.1 – can be found by heading to Settings > General > Software Updates. It’s only a tiny 656MB file, but don’t be fooled by its size, as it’s not an upgrade you want to ignore.

“This update provides important bug fixes and security updates and is recommended for all users,” Apple advises in its release notes.

So why is this iOS change so important?

Apple says that this update blocks a bug that could allow a physical attack to disable a feature called USB Restricted Mode on a locked device. This could then hackers access to personal data. What makes this more scary is that it’s thought to be what’s known as a ‘zero-day’ attack which means it may have already been used in the wild.

“Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals,” the company added.

As soon as you install iOS 18.3.1, you will be protected from future attacks, so it’s worth doing as soon as possible – just remember that your iPhone will need to restart after the download.

Now may also be a good time to switch on Apple’s “Automatic Updates” as this means you will always have the most up-to-date software loaded onto the phone and you don’t have to keep checking to see if things have been installed.

Automatic Updates often occur during the night, which means you’ll wake up with an iPhone that’s ready to go and won’t need rebooting when you need to use it during the day.