Using cat with arbitrary input exposes you to many terminal-side security issues. It is insufficiently complex.
Alternatively use "cat -v" and any terminal escape characters will be escaped.
It can do some sketchy things and rewrite your terminal in weird confusing ways, but afaik most of the out-and-out malicious escape sequences have been patched out at least a decade ago.
Such as?
Cat has long been known to expose you to code execution, among other things.
Any vulnerability in the escape sequence handling of the terminal emulator, and conceivably, depending on what sequences your terminal supports, access to facilities like local file generation or clipboard contents. There have been a number of issues with escape sequences injected into things people might copy and paste from a web page, or in git commit histories, that have done nefarious things.
that wouldn't work nicely with the mouse :)
That's what the on-screen keyboard is for. Even works with the touchscreen, no mouse required! Eminently usable.