Welcome to WebmasterWorld Guest from 18.104.22.168
A long, long time ago I remember updating either Perl or PHP (I forget which), and afterward I had to go through and modify literally thousands of scripts!
..., update to 5.14.4 and hope for the best, or go all in and update to 5.28.2?
PHP4 to PHP5 would have been a headache.
5.26 is the oldest currently supported version