iCloud Private Relay IP Leak: What Safari Users Should Know
Researchers found three WebKit network paths that can bypass iCloud Private Relay, exposing a user's real IP address or DNS path to a specially configured website.
The short version
What you need to know
- Mysk researchers identified DNS prefetching, WebAuthn related-origin requests and WebTransport as network paths that can operate outside WebKit's application-level proxying.
- The issue is conditional rather than a constant leak: a specially configured page must invoke one of the affected mechanisms, and DNS prefetching reveals the network path rather than working exactly like the two direct-IP vectors.
- The researchers say these WebKit bypasses do not affect correctly functioning system-level VPN tunnels, although no privacy tool should be treated as automatically leak-proof.
What happened?
Researchers Talal Haj Bakry and Tommy Mysk reported three WebKit features that can send network requests outside an application-level proxy. For iCloud+ subscribers using Private Relay in Safari, a specially configured website may be able to learn the real public IP address or normal DNS path instead of seeing only the relayed connection.
The three paths are DNS prefetching, passkey-related WebAuthn origin checks and WebTransport connections. The researchers describe WebAuthn and WebTransport as direct IP-disclosure routes. DNS prefetching is better understood as a DNS and network-path leak, so the mechanisms should not be treated as identical. TechCrunch says it reproduced a real-IP disclosure with the researchers' test page.
Why it matters for Apple users
A person may enable Private Relay specifically because they do not want websites to connect browsing activity to their home, mobile or workplace IP address. A page that can selectively bypass that protection may weaken location privacy, network separation or pseudonymous browsing.
This does not mean every Safari request exposes the real IP, nor that Private Relay is switched off entirely. Apple describes Private Relay as a Safari-focused two-relay privacy service, not a full-device VPN. The reported issue concerns specific out-of-band WebKit operations that a site must trigger.
What you can do now
Keep Safari, iOS and macOS updated and watch Apple's security guidance for a fix or mitigation. People with a high-risk need to separate their real IP from browsing activity should avoid assuming that Private Relay alone covers every WebKit connection and should test any privacy setup they rely on.
Do not use random IP-leak test pages that request unusual permissions or credentials. The researchers published a proof of concept, but ordinary users do not need to repeatedly expose their browser to unknown testing sites. Consider whether a reputable system-level VPN, a hardened browser setup or a specialist anonymity tool better matches your actual threat model.
Where a VPN helps — and where it does not
Mysk says a system-level VPN is not affected by these particular WebKit proxy bypasses because the resulting device connections should still travel through the VPN tunnel. That makes the distinction between a Safari-focused relay and a full-device tunnel important.
A VPN is not an automatic anonymity guarantee. Provider logging, DNS configuration, browser fingerprinting, account sign-ins, cookies and software bugs can still identify or track a user. Choose a reputable provider, enable leak protection, keep the app updated and test the setup rather than relying on a logo or privacy slogan.
VPN Rocks view
Private Relay remains useful for reducing routine IP visibility in Safari, but this research shows why application-level privacy features need careful boundary testing. A browser can have more than one networking path, and the least protected path can undermine the strongest one.
For everyday users, the proportionate response is to update and reassess—not panic. For journalists, activists or anyone facing targeted monitoring, treat IP protection as a layered system and verify the exact traffic that each layer covers.
Primary reading
Sources and further reading
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