An integer overflow vulnerability exists in the Unix.map_file function of the OCaml standard library when calculating the product of bigarray dimensions. This overflow can lead to incorrect memory mapping behavior if the dimensions or file size are user-controllable. The issue is fixed by using a safer multiplication function that detects overflow and raises an exception. Versions prior to 4.14.5 and versions from 5 up to but not including 5.5.2, as well as several 3.x versions, are affected.