Apple regularly issues updates to the software powering the iPhone, and sometimes it’s OK to dawdle when it comes to installing them. But that’s not the case with its latest — an upgrade that Apple released Wednesday to close a security hole that could allow hackers to seize control of iPhones and several other popular Apple products.

Security experts are warning that everyone with an iPhone should install the update as soon as possible to protect all the personal information many people store on a device that’s become like another appendage for many.

Without the latest update, a hacker could wrest total control of Apple devices, allowing the intruder to impersonate the true owner and run any software in their name.

The company also issued fixes to block the security threat on iPads and Macs. The flaw may already have been “actively exploited,” according to the company, which has had to fix other security problems with the earlier this year.

HOW DO I FIX THIS?

The good news? There’s an easy fix: you should be able to find easily. Start with the Settings app, the one with an icon featuring what looks like gears in an old watch. Go into the “General” section, then “Software Update.” The page you see will offer simple instructions or, if your device has already updated, a message to that effect.

The whole process typically only takes a few minutes, according to security experts.