Your real IP address leaks when you browse with Private Relay on in Safari

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iCloud Private Relay is Apple's opt-in privacy feature that routes Safari traffic through two relays so websites never see the user's real IP address. Researchers Talal Haj Bakry and Tommy Mysk found three features in WebKit, Apple's browser engine, that ignore the browser's proxy configuration and connect directly from the device, defeating that guarantee: DNS prefetching resolves hostnames over the device's normal DNS path; WebAuthn Related Origin Requests make the operating system's credential service fetch a validation file itself; and WebTransport opens a direct HTTP/3 connection.

The WebAuthn path is the most serious, because it needs no user interaction at all. Any website can configure the passkey API — or merely pretend to support passkeys — so that WebKit reveals the real IP address. There is no passkey prompt, no permission dialog, and nothing on screen to indicate the leak occurred, so a user who has deliberately enabled Private Relay has no way to notice their protection silently failed.

Because the fault is in WebKit rather than in Safari specifically, and because every browser on iOS and iPadOS must use WebKit, the leak is not confined to Safari. Chrome, Firefox, Edge and Brave on iOS are affected, as are privacy-focused browsers including OnionBrowser and Psylo, which Mysk co-develops. That makes the bug particularly damaging for users who chose these tools precisely to avoid being located or deanonymized.

Steps to reproduce:

  1. Enable iCloud Private Relay on an iPhone, iPad or Mac (Settings/System Settings → Apple Account → iCloud → Private Relay).
  2. Open Safari, or any browser on iOS/iPadOS.
  3. Visit the researchers' test page at https://leaks.psylo.app/ — or any page that issues a WebAuthn Related Origin Request, triggers DNS prefetching, or opens a WebTransport connection.
  4. The page displays the device's real IP address rather than the Private Relay egress address, with no prompt or visible indication that a direct connection was made.

Workaround: Use a full-device VPN rather than relying on Private Relay, since a VPN captures traffic below the browser layer and therefore covers the direct connections that bypass the proxy. Disable Private Relay on untrusted networks rather than assuming it protects you, and treat it as a tracker-mitigation feature rather than an anonymity tool. Users with a genuine need for IP anonymity (journalists, activists, researchers) should not depend on Private Relay or on iOS browsers built for privacy until this is patched. The test page at https://leaks.psylo.app/ can be used to confirm exposure.

Severity: Major (silently and completely defeats the sole purpose of a privacy feature, exploitable by any website with no user interaction and no visible sign, affects every browser on iOS/iPadOS, and no patch is available — but there is no code execution, data loss, or account compromise)
First seen: 4 August 2026
Affected product: iCloud Private Relay
Affected platforms: iOS, iPadOS and macOS — Safari plus every third-party browser on iOS/iPadOS, since all are required to use WebKit (Chrome, Firefox, Edge, Brave, OnionBrowser, Psylo)
Affected versions: iOS/iPadOS 26 and later for the DNS prefetching leak, iOS/iPadOS 26.4 and later for the WebTransport leak; the WebAuthn Related Origin Request leak is not tied to a stated version range, and no source gives precise macOS or Safari version numbers
Fixed versions: Not yet available (Apple has indicated a fix is planned, reportedly for Fall 2026; no version announced)

Links:

icloud-private-relay
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Your real IP address leaks when you browse with Private Relay on in Safari