For millions of users, the “Always-On VPN” toggle in Android settings is more than just a convenience; This proves a digital promise. It is the primary safeguard for those who believe that no single packet of data should ever leave their device without being encrypted and routed through a secure tunnel. However, a newly confirmed Android 16 VPN bypass has effectively turned that guarantee into a suggestion.
A technical paper published by a security researcher has revealed a critical flaw in Android 16 that allows malicious applications to circumvent VPN protections entirely. The vulnerability renders both the “Always-On VPN” and the “Block connections without VPN” settings ineffective, allowing traffic to leak outside the encrypted tunnel. When this happens, a user’s real IP address is exposed to the open internet, opening the door to the exact tracking and surveillance that VPNs are designed to prevent.
The discovery is compounded by a frustrating response from Google. After the bug was reported through the Android Vulnerability Reward Program, Google closed the issue, marking it as “Won’t Fix.” The company’s justification is that the flaw falls outside of its current threat model, leaving users to rely on the hope that they never install a compromised app.
The “Won’t Fix” Dilemma
The vulnerability was first brought to light by Yusef, a Zurich-based security researcher known on X as @cybaqkebm. Yusef reported that the features meant to provide a hard guarantee against data leaks are “not that reliable.” Despite the severity of the bypass, Google’s refusal to patch the issue suggests a fundamental disagreement between the company and the security community regarding what constitutes an acceptable risk.
A Google spokesperson stated: “This issue only affects devices that have downloaded a malicious app. Android users are automatically protected against known malicious apps by Google Play Protect.”
This response shifts the burden of security from the operating system’s architecture to the user’s behavior. While avoiding malicious software is a basic tenet of digital hygiene, relying solely on Google Play Protect is a gamble. Security historians and researchers often point out that “known” malicious apps are only identified after the damage has begun. In one recent instance, malicious software remained in the Play Store long enough to be downloaded 7.3 million times before being detected and removed.
How the Android 16 VPN Bypass Works
From a technical perspective, the leak occurs through a specific mechanism in the system’s connectivity management. According to Yusef’s report, the vulnerability centers on a Binder method within the ConnectivityManager called registerQuicConnectionClosePayload.
This method accepts a UDP socket and an arbitrary byte buffer from any caller that possesses the INTERNET and ACCESS_NETWORK_STATE permissions—both of which are automatically granted to almost every app on the platform. When the registered socket expires or “dies,” the system_server sends the buffer across the socket’s original network. Critically, this process occurs without a permission check, without payload validation, and with no awareness of whether the calling application is supposed to be locked down by a VPN.
By using a specific technique to slip past the fwmark server, a malicious app can use this primitive to send data—including the user’s real IP address—directly to the internet, bypassing the VPN tunnel entirely. This means the vulnerability affects all VPN apps on the Android 16 platform, regardless of the provider or the strictness of the user’s configuration.
A Pattern of Privacy Limitations
The Android discovery has sparked a wider conversation about whether any mobile operating system can truly guarantee a “leak-proof” VPN experience. Evidence suggests that Apple’s iOS is not immune to similar architectural limitations, though Apple is more transparent about them in its legal documentation.
In a legal posting regarding VPNs and privacy dated December 12, 2025, Apple confirmed that “not all your device’s network traffic will be routed through an active VPN.” The company noted that if a developer specifies a required connection type—such as mobile data only—that traffic is excluded from active VPN configurations. While iOS allows VPN providers to attempt to override these choices, the system does not provide the same absolute lockdown that users often assume exists.
| Feature/Issue | Android 16 | iOS / iPadOS |
|---|---|---|
| VPN Bypass Status | Bug-driven (Vulnerability) | Design-driven (Configuration) |
| Official Stance | “Won’t Fix” (Outside threat model) | Disclosed in legal privacy terms |
| Primary Risk | Real IP leak via malicious apps | Traffic exclusion via app settings |
| Mitigation | Graphene OS or manual config | VPN provider overrides |
Current Mitigations and Risks
For the average user, there is currently no simple “toggle” to fix this vulnerability in the standard version of Android 16. There are two primary ways to mitigate the risk, though neither is accessible to the general public.
First, users can manually amend a DeviceConfig setting. However, What we have is a complex process that requires deep technical knowledge. Yusef has warned users to attempt this “only if you understand the implications and on your own risk,” as incorrect changes to device configuration can lead to system instability.
Second, users can switch to Graphene OS, a privacy-hardened version of Android that has already resolved the issue. While this is the most effective solution, it requires unlocking the bootloader and installing a custom operating system—a hurdle that most consumers are unwilling or unable to clear.
For those staying on standard Android 16, the only remaining defense is extreme caution regarding app installations. Users should only download apps from official sources and prioritize those with the VPN badge in Google Play, though as previously noted, this is not a foolproof shield against zero-day threats.
The industry is now watching to see if pressure from app vendors and the security community will force Google to reconsider its “won’t fix” designation. As more users move to Android 16, the potential for wide-scale IP leakage becomes a significant privacy concern that may require a formal security patch via the Android Security Bulletins.
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