Apple just released an update for iOS and iPadOS 15.0.2, which fixes a security bug on Apple devices. Notably, Apple says that the bug "may have been actively exploited," which means you should update your device right now.
Monday's update fixes a memory corruption issue that might have allowed some apps to "execute arbitrary code with kernel privileges," according to Apple's support page. Translation? Hackers could use the vulnerability to take over your iPhone or iPad. Updating your device should close the vulnerability.
This is Apple's second security update in a month, following September's.