Apple itself didn’t report a security breach.
iPhone, iPad, and Mac were found exploitable, and iPhone and iPad were patched to iOS and iPadOS 15.6.1, and macOS to 12.5.1.
There’s no good way to look at RAM, so I’ll assume that was a reference to insufficient main storage. How much storage do you have on this iPhone? The 16 GB configuration is commonly a problem on more recent versions (it’s ~full), and running out of free storage will cause problems with performance and with stability.
That error is some node.js code and which get used all over, so unclear what’s happening with that. If the iPhone device ran out of storage, things can get confused.
If the configuration is causing problems, create a backup, and then perform a factory reset. If you’re unsure of what is installed, maybe don’t restore.
Restore your iPhone, iPad, or iPod to factory settings - Apple Support (links to backup and restore are included there)
Also change your Apple ID password, review the Apple Security Recommendations in Settings > Passwords, add two-factor authentication if not already enabled, and review your security. Links to more info:
If you think your Apple ID has been compromised - Apple Support
https://help.apple.com/pdf/personal-safety/en_US/personal-safety-user-guide.pdf
Based on what you’re posting, this could well be a corrupt or full device. A breach is certainly possible, but those have been less than common, and recent iPhone and iPad security attacks have been targeted at people and groups, and have not been more general.