Apple is pushing out a new update for the iPhone OS, taking it to iOS 14.4.
The update addresses a flaw which is being actively exploited, with Apple noting:
Impact: A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Impact: A malicious application may be able to elevate privileges. Apple is aware of a report that this issue may have been actively exploited.
The description suggests that merely visiting a website may be enough to compromise a device, but Apple has not released details about the exploits in question.
According to Apple, the flaws affect much more than the iPhone, with iPhone 6s and later, iPad Air 2 and later, iPad mini 4 and later, and iPod touch (7th generation) all affected.
While most people wait a few weeks before updating in this occasion it may be wise to update sooner rather than later, via going to Settings > General > Software Update and then tap “Download and Install” at the bottom of that page.