Earlier today, reports emerged that WPA2 Wi-Fi encryption protocol is fundamentally flawed, and can easily be cracked to intercept and read traffic sent across a wireless network. And now we are finally getting details about the scale of the problem.

Known as KRACK, the attack sees a malicious actor trick any victim into using a compromised encryption key. And according to the reports, Linux and Android-based users are most at risk.

Matty Vanhoef, who uncovered the issue, says that the 41 percent of Android devices are vulnerable to an exceptionally devastating variant of the attack, which makes it “exceptionally trivial” to intercept traffic. “If your device supports Wi-Fi, it is most likely affected,” says Vanhoef.

The issue is not just limited to Android or Linux. Vanhoef named many other platforms, saying “During our initial research, we discovered ourselves that Android, Linux, Apple, Windows, OpenBSD, MediaTek, Linksys, and others, are all affected by some variant of the attacks.”

Vanhoef also suggested that the issue can be resolved with a backwards-compatible software patch. And the solution should arrive soon, as he notified vendors about the flaw in July, with a broader notification issued in August.

An update and a security patch is great, but it’s worth remembering that there are hundreds of millions of devices affected. And that include embedded systems like routers, printers, and other Wi-Fi-enabled smart home devices, which aren’t as straightforward to update.