Millions of Britons are being urged to update their iPhones and other Apple devices after the technology giant confirmed the discovery of a major security flaw.

The technology giant has issued software updates for the iPhone, iPad, Apple Watch and Mac computers to fix a newly uncovered software issue, telling users the update “provides important security updates and is recommended for all users”.

The flaw could potentially allow hackers to take complete control of affected devices, cybersecurity experts said, and Apple confirmed that it was “aware of a report that this issue may have been actively exploited”.

But industry experts have encouraged Apple users to “stay calm” on the issue.

There have so far been no confirmed reports of specific cases where the security flaw had been used against people or devices.

Apple’s published disclosure of the issue said it was reported to them by an anonymous researcher.

The update has been made available to the iPhone 6s and later, all models of the iPad Pro, the iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and the iPod touch (7th generation).

Mac users running macOS Monterey are also being encouraged to update.

Cybersecurity experts have encouraged the public to update their devices as soon as possible to protect themselves against the flaw, but also urged people not to panic.

Brian Higgins, security specialist at Comparitech, said: “It’s very rare for them to go public like this, which means everyone should take this threat seriously and update as soon as they are able.

“If Apple think it’s so serious that they need to go public, then if you haven’t already installed iOS 15.6.1 you need to go and do it right now.”

Sam Curry, chief security officer at Cybereason, said: “Regardless of Apple’s recent disclosure of a serious vulnerability affecting millions of iPhones, iPads and Macs, it wouldn’t be prudent for anyone to panic.

“While the vulnerability could allow threat actors to take full control of a device, stay calm and simply get control of your devices and download the software updates available from Apple.

“Do that and move on. In a rare case, we will find out how threat actors were able to exploit the current vulnerabilities. Overall, follow Apple instructions if you think you are infected and consult your IT department at work, school, etc, as needed for more information.

“With billions of Apple devices in use around the world, security can’t be a luxury for Apple and it’s not, it’s a responsibility they take seriously.

“Failing is OK as no-one is perfect. Failing consistently is not. Generally, Apple is a more secure platform, but they must continue to invest and demonstrate that continued commitment going forward.”