iPhone users urged to update iOS immediately due to dangerous darksword vulnerability

Apple has released an out-of-schedule update for users of older system versions. This is a rare case where the company is issuing backported patches specifically for those who have not yet moved to iOS 26.

What Happened

On April 1, 2026, Apple made the iOS 18.7.7 update (and the corresponding iPadOS version) available to a much wider range of devices. Previously, this build had been limited to the oldest models (such as iPhone XS, XR, and similar), which physically do not support iOS 26. The patch has now been expanded to protect all iOS 18 users who, for various reasons, do not want or cannot upgrade to the new system version.

The update fixes a critical chain of vulnerabilities known as DarkSword—a powerful exploit kit that has been actively used in attacks and was recently made publicly available.

How DarkSword Works

The vulnerability is a chain of six exploits affecting iOS versions from 18.4 to 18.7. The attack is completely invisible to the user: simply opening a compromised website in the Safari browser is enough (a so-called watering hole attack or drive-by download). No additional clicks, downloads, or actions are required.

The exploits take advantage of vulnerabilities in the JavaScriptCore engine (memory), ANGLE, the iOS kernel, and mechanisms for bypassing Pointer Authentication Code (PAC) protections in dyld. After a successful compromise, an attacker can install malware and gain access to sensitive data, including credentials and information from cryptocurrency wallets.

After compromise, the malware quickly collects data and then deletes itself—a “hit-and-run” approach that makes detection more difficult.

Researchers from Google Threat Intelligence Group (GTIG), Lookout, and iVerify reported that DarkSword has already been used by multiple groups, including ones believed to be linked to Russian interests (UNC6353). After the source code was leaked on GitHub, the risk of widespread use increased sharply.

Why Apple Took This Unusual Step

iOS 26 already included protection against DarkSword (fully implemented starting from version 26.3). However, a significant portion of users (according to some estimates, about 25% of all iPhones) continues to run iOS 18. Many avoid upgrading due to new features (such as Liquid Glass) or concerns about performance on older devices.

Instead of forcing everyone to move to iOS 26, Apple decided to release a dedicated update within the iOS 18 branch. Users with automatic updates enabled will receive the patch automatically. Those who have auto-update disabled will be prompted to install iOS 18.7.7 or upgrade directly to iOS 26.

What to Do Right Now

Update as soon as possible. Go to Settings → General → Software Update and install the available update.

If your device supports iOS 26, it is recommended to upgrade to it to receive all the latest security improvements and features.

For devices that cannot go beyond iOS 18, updating to version 18.7.7 is essential.

As a temporary protective measure, Apple and security experts recommend enabling Lockdown Mode. It significantly reduces the attack surface, although it makes some features less convenient to use.

In Brief

Apple has urgently released iOS 18.7.7 to protect millions of iPhones still running an older system version from the powerful DarkSword exploit kit. The vulnerability allows full device compromise simply by visiting a malicious website in Safari. After the code leak, the threat became widespread. Update immediately—this is one of those rare cases where delay can truly result in the loss of personal data and access to cryptocurrency wallets. Users on iOS 26 do not need to worry, as they are already protected.