I think you are wrong here - 4.1 will use Fedora 32 in dom0, and that
*will* have cryptsetup-2.3.4-1.fc32.(Available as security update in
32 since Sept 2020)
Qubes 4.0 which uses Fedora 25 in dom0 does have the older version.
In any case, this will only bite, I think, if you allow an attacker
to attach a crafted image to dom0 - in that case you are hosed in any
case imo.