silverstripe-framework/admin/scss/_SecurityAdmin.scss

.SecurityAdmin {
	// Same rules in .member-profile-form
	.permissioncheckboxset, .permissioncheckboxsetfield_readonly {
		.optionset {
			li {
				float: none;
				width: auto;
			}	
		}
	}
}

.cms .cms-content .SecurityAdmin { //datagrid overflow on Security Admin	
	.cms-content-fields {
		overflow-y:auto;
		.aligned-right-label { //align the label with the parent group field in add new group
			margin-left:$grid-x*23;
			padding:$grid-x 0;
		}
	}
}