Unpatched iOS sandbox escape exposes crypto wallet data on recent versions

Cryptocurrency exchange Binance has issued a warning about a critical security vulnerability affecting iPhones running iOS 26 and 27. The flaw, known as worse_query, allows malicious applications to bypass the iOS sandbox and access sensitive data stored by other apps, including private keys and seed phrases. Apple’s most recent software updates do not appear to address this specific issue, leaving users potentially exposed until a patch is released.

What happened

Researchers forcequit and 0xjohnny published the exploit code on GitHub on Sunday, just one day before Apple rolled out its latest iOS updates. The vulnerability enables an app to read files from other applications’ data containers, effectively breaking the isolation that normally keeps app data separate and secure. This poses a severe risk for cryptocurrency users, as wallet apps often store critical credentials locally on the device.

Binance advised its users to take immediate precautionary steps, though it did not report any active thefts or attacks linked to the exploit. The exchange recommended deleting any apps installed from untrusted sources, such as those sideloaded or manually signed, and ensuring that both iOS and all installed apps are up to date. For users who suspect their device may have been compromised, Binance suggested moving funds to a new wallet created on a clean device and resetting all active login sessions.

The researchers stated that they released the code earlier than planned because Apple was slow to respond to their reports, and misinformation was spreading online. Forcequit noted on X that "Apple was stalling on responding to me and people started larping with it on here." Despite the public release, neither the researchers nor Binance have confirmed any real-world exploits resulting in financial loss.

How it works

The worse_query exploit targets the iOS sandbox mechanism, which is designed to prevent apps from accessing each other’s data. To function, the exploit requires an app to set up an App Group container, a feature typically used for sharing data between apps from the same developer. Once this container is established, the proof-of-concept code can access every app’s data container on the device, and even some system folders on iOS 27.

Developer Christoph Kolbicz has already built a functional file manager called WQ Files using this exploit. This app can be installed via sideloading tools like AltStore and SideStore, which automatically configure the necessary App Group when linked to an Apple ID. WQ Files allows users to view, edit, delete, and clear data from other apps without requiring a jailbreak or a kernel-level exploit. It remains unclear whether an app distributed through the official App Store could leverage this vulnerability, as no one involved has confirmed such a possibility.

Key details

• The vulnerability affects iPhones running iOS 26 and 27, with some reports suggesting support for iOS 27.2.1.
• The exploit, named worse_query, was released by researchers forcequit and 0xjohnny on GitHub.
• Apple’s recent updates, iOS 27.2.1 and iOS 26.7.3, fixed iMessage and Bluetooth issues but did not list a fix for this sandbox escape.
• The exploit requires an App Group container, which sideloading tools can automatically create.
• No confirmed attacks or thefts have been reported, but the risk to local crypto wallet storage is high.
• Binance advises users to remove sideloaded apps and move funds if a breach is suspected.

Why it matters

For software engineers and security professionals, this incident highlights the fragility of mobile sandboxing when advanced inter-app communication features are involved. The fact that a non-jailbroken device can have its app data accessed by another installed application undermines a core security promise of the iOS ecosystem. Developers building financial or security-sensitive applications must assume that local storage may not be entirely safe if a user has installed untrusted software.

The delay in Apple’s response and the subsequent public release of the exploit also underscore the challenges in responsible disclosure. When vendors do not communicate timelines or acknowledge severity, researchers may feel compelled to go public to warn users, even if a patch is not ready. This dynamic creates a window of vulnerability where attackers can develop weaponized versions of the proof-of-concept code before a fix is available.

What you can do

• Delete any apps installed from untrusted sources, including those sideloaded via AltStore or SideStore.
• Update your iPhone to the latest available iOS version, although note that a specific fix for this issue is not yet confirmed.
• If you use a crypto wallet app, consider moving your assets to a new wallet generated on a completely clean device.
• Reset all active login sessions for your cryptocurrency exchanges and wallet services.
• Monitor official security notes from Apple for future mentions of sandbox fixes or related patches.
• Avoid installing file managers or utilities that require broad system access unless they are from verified, trusted developers.