Apple’s promise of enhanced digital privacy is facing new scrutiny following reports that its iCloud Private Relay service may be failing to protect user identities. Recent findings from security researchers indicate that a critical flaw in the underlying technology of iOS browsers allows websites to bypass anonymity protections and view a user’s real IP address. This discovery undermines one of the primary selling points of Apple’s premium subscription service, leaving users potentially exposed to the very tracking they sought to avoid.
What happened
Security researchers Tommy Mysk and Talal Haj Bakry identified a significant vulnerability within WebKit, the browser engine that Apple requires all iOS browsers to use. The issue is linked to how the system handles WebAuthn, the technical standard behind “passkeys,” which are intended to provide a more secure alternative to traditional passwords.
The researchers discovered that when a website requests or even pretends to support passkey authentication, the request is not handled by the browser itself. Instead, the request is triggered by the operating system’s internal credential services. Because these system-level requests bypass the Safari browser’s standard data path, they also bypass the iCloud Private Relay proxy. As a result, the destination server receives the device’s actual IP address rather than the masked address provided by Apple.
This vulnerability was verified by independent tests, confirming that a malicious site can easily bypass Private Relay to unmask a visitor. Furthermore, the flaw extends beyond Safari to impact other privacy-centric apps like OnionBrowser, which relies on the same WebKit framework to provide Tor network access on iOS.
Context
iCloud Private Relay is a key feature of the paid iCloud+ subscription. Apple markets it as a tool to prevent network providers and websites from profiling users based on their DNS records and IP addresses. By routing traffic through two separate internet relays, the service is designed to ensure that no single party—including Apple—can see both who the user is and what site they are visiting.
It is important to distinguish Private Relay from a traditional Virtual Private Network (VPN). While a VPN typically encrypts all traffic from an entire device, Private Relay is more limited, primarily protecting traffic within Safari. This architectural limitation is at the heart of the current issue: because the passkey “fetch” happens at the operating system level rather than the browser level, it falls outside the narrow scope of Private Relay’s protection.
This is not the first time Apple’s privacy-focused features have encountered problems. Recently, the “Hide My Email” feature was also found to be leaking real user addresses. In that instance, reports indicated that Apple had been aware of the bug for over a year before implementing a fix, leading to concerns regarding the company’s responsiveness to security vulnerabilities in its paid products.
Why it matters
The discovery of this leak is particularly troubling because it affects the very users who are most concerned about their digital footprint. For individuals in sensitive environments who rely on tools like OnionBrowser for anonymity, the exposure of a real IP address can have serious real-world consequences.
Because Apple mandates the use of WebKit for all browsers on its mobile platform, developers of third-party apps have very little room to implement their own fixes. The creator of OnionBrowser noted that the root cause of the leak is entirely within Apple’s control. Until Apple updates the core WebKit engine and the way iOS handles credential fetches, users remain at risk of being tracked even when they believe they are protected.
As of now, Apple has stated that it is investigating the reports. However, the situation highlights a growing gap between the marketing of “Privacy. That’s iPhone” and the technical reality of how integrated system services can inadvertently compromise user data. For those who require absolute anonymity, these findings suggest that integrated browser-level proxies may not be a sufficient replacement for a system-wide VPN or the official Tor Browser on other platforms.