If your iPhone is one of the ones listed, you need to make sure you’re on the latest iOS software as soon as you can.

“There’s no workaround or user behavior that meaningfully mitigates this risk,” says Keeper Security’s Darren Guccione.

Hacking the iPhone has long been considered a rarified endeavor, undertaken by sophisticated nation-states against only their most high-value targets. But a discovery by a group of Google researchers ...