Hi, Modify like below.

use vg.setLimit(1000); before vg.query(); which lets you to limit the number of gliderecord that returns after satisfying the gliderecord condition.

runit();

function runit() {
var vg = new GlideRecord('sn_vul_vulnerability');
vg.addEncodedQuery('assignment_group.nameISEMPTY^vulnerability_group_rule=2d8025e41b887c102cc9975f034bcb67^ORvulnerability_group_rule=2ad2fb201bdf6410151c975f034bcb07^ORvulnerability_group_rule=ce9ca1f8db3bdc1090d359e5ca961959^ORvulnerability_group_rule=b0548ab0db3ee4508785dc62ca961942^ORvulnerability_group_rule=5965adc2dbf3985090d359e5ca9619fa^ORvulnerability_group_rule=3ff5f021dbb33fc4399475e6f4961983');
vg.query();
vg.setValue('assignment_group', '6bffdcf8dbe2f41813c6dff648961975');
vg.updateMultiple();
}

or

runit();

function runit() {
var vg = new GlideRecord('sn_vul_vulnerability');
vg.addEncodedQuery('assignment_group.nameISEMPTY^vulnerability_group_rule=2d8025e41b887c102cc9975f034bcb67^ORvulnerability_group_rule=2ad2fb201bdf6410151c975f034bcb07^ORvulnerability_group_rule=ce9ca1f8db3bdc1090d359e5ca961959^ORvulnerability_group_rule=b0548ab0db3ee4508785dc62ca961942^ORvulnerability_group_rule=5965adc2dbf3985090d359e5ca9619fa^ORvulnerability_group_rule=3ff5f021dbb33fc4399475e6f4961983');
vg.query();
while (vg.next()){
vg.setValue('assignment_group', '6bffdcf8dbe2f41813c6dff648961975');
vg.update();
}
}