Optimize a regex validating a version string
Since the second and third segment are similar, you can put them in a non-capturing group with quantifier.

If you allow/want the first digit to be \$ 0 \$ in your first group, the expression is ok as it is. Otherwise, you can restrict the first digit to be [1-9].

You can have + quantifier instead of {1,} as they are essentially the same :)

^[0-9]{2}(?:\.[0-9]{1,2}){2}\.[0-9]+$


and for unpadded version matches:

^[1-9][0-9](?:\.[0-9]{1,2}){2}\.[0-9]+$