What is the highest version of php supported on the highest cake 2?

We are now upgrading our app to cake 2.10 and we work toward supporting PHP 7.4 but I wonder if we can possibly support PHP 8?

Going to php 8 is probably stretching it, I read the requirements you really should consider during the upgrades and get up-to-date to 4.*.

Just my suggestion.

FYI: CakePHP is EOL since June 15, 2021 and therefore won’t recieve any further PHP support updates.
But there are other people forking cakephp 2 and making it PHP 8.0/8.1 compatible which you can find in e.g. this Github issue.