Public Apple iOS sandbox escape lets apps read other apps' data

A proof of concept for an iOS sandbox escape called worse_query has been public since 8 November, and exchanges and security firms are now warning crypto wallet users about it. Its developer, who posts as forcequit, announced it as a zero-day sandbox escape for iOS 26 and 27, made with a second researcher, and published the code on GitHub. The README says it works on iOS 26.0 to 26.7.2 and on iOS 27.2.

The sandbox is what normally keeps each iOS app inside its own container. According to the README, an app using worse_query can reach the data containers of other installed apps, app extensions and internal daemons, the shared App Group containers, and on iOS 27 some system containers. An app has to set up an App Group container of its own to use it. The developer describes it as a proof of concept for developers, and says it is not a jailbreak and never will be. It replaces an earlier escape by the same developer, bad_query, which covered iOS 26.0 to 26.6.1 and an iOS 27 beta.

Tools built on it within two days

Other developers have already packaged it. One released a file manager for iOS 27 that browses, edits, backs up and clears other apps' data without a jailbreak, and the customisation tool Erosion swapped bad_query for worse_query in its version 0.3. These are tools people install deliberately, but they show that the code works in ordinary apps, outside a lab.

Why wallet users are being warned

SlowMist put out an alert at 06:46 UTC on 10 November. It says the flaw does not steal funds by itself; the risk starts when a user installs an app from an untrusted source, such as a sideloaded IPA. A wallet that stores its seed phrase, keystore or WebView cache in plaintext on the phone could then have it read by that app. SlowMist told wallet developers to stop storing sensitive data in plaintext and told users who have installed an untrusted app on a phone with wallets to move their funds to a new wallet created on a clean device.

Binance followed at 09:56 UTC, saying seed phrases, private keys and login credentials are at risk across the ecosystem and that the problem is in iOS, not specific to Binance. It told users to delete sideloaded or manually signed apps, update iOS and all apps, and, if they suspect a breach, move funds to a new wallet on a clean device and reset all active login sessions.

The two warnings name different versions. Binance lists iOS 26.7.1, 27.0.1 and 27.2. The README and SlowMist give the whole range from 26.0 to 26.7.2 plus 27.2, so phones on earlier iOS 26 releases are in the same position.

No word yet from Apple

Apple released iOS 27.2.1 and iOS 26.7.3 on 9 November, the day after the code went public. Neither security note mentions a sandbox escape or credits the worse_query developers. Apple has not said whether either update blocks it, so updating is worth doing but should not be treated as a proven fix.