An Unpatched iPhone Flaw Could Let a Rogue App Read Your Other Apps' Data. Here's How to Stay Safe

Security researchers have published details of a flaw in iOS, the software that runs your iPhone, which they say could let a malicious app read files belonging to your other apps, including banking and finance apps, and they say Apple hasn't fixed it yet. The crypto exchange Binance has warned its customers about it this week, so I wanted to explain what's going on, whether you need to worry, and the simple habits that keep you safe until Apple puts out an update.

What's been reported

Normally every app on your iPhone lives in its own sealed box, which Apple calls a sandbox, so your banking app can't see inside your email app and a game can't see inside either of them. Two researchers, who go by @0xjohnny and @forcequitOS online, say they've found a way around those walls. They've named the flaw worse_query and published a working demonstration of it, known as a proof of concept, on GitHub, which is a website where developers share code.

Binance then posted a warning on X, which AppleInsider picked up, saying a malicious app could use the flaw to read files from other apps and put login details at risk, along with the private keys and recovery phrases that crypto users rely on to access their money. Binance says it affects iOS 26.7.1, iOS 27.0.1 and iOS 27.2, and it made a point of saying this is an iPhone-wide problem rather than something unique to its own app.

According to 9to5Mac, other developers have already built apps using the technique, including a file manager that can look at, change and delete other apps' data without the iPhone being jailbroken, which means hacked to remove Apple's built-in restrictions.

There is some reassuring news too, because The Hacker News reports that neither Binance nor the researchers know of any attacks or crypto thefts using the flaw so far.

What Apple has said so far

Apple hasn't publicly acknowledged the flaw yet. The notes for its latest security updates, including iOS 27.2.1, which is the newest version at the time of writing, don't mention a fix, and @forcequitOS has said it isn't fixed in iOS 27.2.1 or in the first test (beta) version of iOS 27.3 either. The researchers describe it as a zero-day, which is the term for a flaw that has been made public before there's a fix for it. You can keep an eye on what Apple fixes in each update on its security releases page.

Am I at risk?

The important thing to understand is that this flaw can't do anything by itself. A malicious app has to be installed on your iPhone first, and then it would use the flaw to reach into your other apps. That's why Binance's advice puts the focus on apps installed from untrusted sources, meaning apps that have been sideloaded, or put on the phone from outside Apple's App Store.

What to do now

• Keep your banking and finance apps up to date. Open the App Store, tap your profile photo in the top right corner, and you'll see your app updates listed there, so you can update them all in one go.
• Keep your iPhone up to date. Go to Settings, then General, then Software Update, and install anything waiting for you.
• Check your passwords. Have a look in your passwords app for any warnings about your details, and change anything it flags.
• Remove apps from outside the App Store. Binance recommends deleting any apps installed from untrusted sources, such as sideloaded apps.
• If you think something is wrong. Binance suggests signing out of all your active logins, and for crypto holders, moving funds to a new wallet set up on a different device that you know is clean.

What I think

I wouldn't be too worried about this, because it needs a malicious app on your phone before it can do any harm. It is worth checking your passwords app to see if there are any warnings on your details anywhere, though, as that's a good habit whatever the news.

Unfortunately modern banking means you have to manage things online, so stopping using your banking app isn't really the answer. If you'd like written clarification about how you're protected, it may be worth contacting your bank, but since Apple hasn't publicly acknowledged the flaw yet, that may be something they refuse to do.

When Apple releases a fix

Install it straight away. My advice with security fixes is always to get them done immediately, and this one is no different, so when an update appears in Settings, don't leave it for another day.

If you're not sure whether your iPhone and apps are up to date, or you'd like a hand going through your passwords, you can ask iHelp AI at /chat for quick questions, or book a session and we'll help you remotely anywhere in the UK or in person across Dorset.

Alex