Apple's Private Relay Leaks Real IPs via Passkey Fetches

Apple's iCloud Private Relay, one of the marquee privacy features on iPhone, reportedly does not cover a code path a lot of privacy-conscious users would assume it does. Security researchers Tommy Mysk and Talal Haj Bakry told 404 Media that any website supporting, or pretending to support, passkeys can see the user's real IP address even when Private Relay is turned on.

The mechanism Mysk describes is that the passkey fetch is issued by iOS's own credential service rather than by Safari, so it never enters Private Relay's proxied path. In the researchers' own write-up, a page can set the passkey's rpId to a host of its choosing and the fetch fires even without user interaction, handing the destination server the device's real network. 404 Media says it independently verified the exposure through a test site.

Two related WebKit paths behave the same way. DNS prefetching, which became available on iOS with version 26.0, lets a page embed unique per-visitor hostnames in link tags and watch the queries arrive at its own authoritative DNS server from the visitor's real network. WebTransport, publicly available in iOS 26.4, opens HTTP/3 connections directly from the device. Because Apple requires every browser on iOS to use WebKit, none of this is a Safari-only problem, and the researchers say OnionBrowser, the Tor-based iOS app, is caught up in it. The official Tor Browser from the Tor Project is not.

The honest caveat is that most of this rests on the researchers' own testing plus 404 Media's verification. Apple reportedly called the issue 'dire' but gave no timeline for a fix, and the reporting does not say whether Apple knew about the passkey path before disclosure or how many sites may already have collected leaked addresses. Take the specifics as reported, not settled.

The near-term read is workable. Users with a serious threat model should stop relying on iOS-based Tor wrappers and use the desktop Tor Browser, and anyone building on iOS that assumes Private Relay covers all outbound traffic should treat it as covering Safari's own network calls and nothing else until Apple patches WebKit.