New research suggests nearly one billion Android phones are capable of being hacked simply by receiving a picture via text, according to WKRN News 2.

The text doesn’t even have to be opened for malware to download.

The bug allows hackers to take full control of all the phone’s functions, and all Androids made in the last five years are at risk.

It could be the biggest smartphone flaw ever discovered.

Zimperium, the company that identified the flaw, says it told Google about it in April and even provided a fix. But after more than three months, the fix still isn’t widely available.

Google told CNN it has sent a fix to its partners, but it’s unclear the message is getting out to users.