The general rule is that you should not use an apostrophe to form the plurals of nouns, abbreviations, or dates made up of numbers: just add -s (or -es, if the noun in question forms its plural with - es).
However, it is not clear from that answer what should be done if the noun in question uses does not end in either -s or -es.
What is the correct plural abbreviation for Curriculum Vitae?
I think the plural is Curriculum Vitarum (or possibly Curricula Vitae), which would make the plural abbreviation CV too. Use of the -s suffix suggests Curriculum Vitaes (or possibly Curriculums Vitae) which seems wrong.
What is correct?