What about:

$WHERE = join ' OR ', map { X => $_ }, @ARRAY;
$DB->update(
   { table => 'table',
     fields => { Y => 0 },
     where => $WHERE
   } );
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Update: Bugs always appear *after* posting :). [...] I misunderstood DBIx::Abstract documentation. Here's my next attempt. It's a bit more complicated though. Fill @WHERE with enough 'OR's and then place the hashrefs over the even elements:

my @ARRAY=qw/foo bar baz/;
my @WHERE=('OR') x (2*@ARRAY - 1);
for (0 .. $#ARRAY) {
  $WHERE[2*$_] = { X => $ARRAY[$_] };
}
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