You could put the variables into some other package which exists just to hold them e.g.

#!/usr/bin/perl
use strict;
use warnings;

sub create_f {
    my $func = shift;
    return sub {
        $MyBucket::var = "xpto";
        &$func;
    }
}

my $function = create_f( 
    sub { print ">> $MyBucket::var <<\n" }
);

$function->();
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