I found the nutritional label, which reports 10 grams of sugar per packet. That, to me, is reasonable. I did not look up the nutritional information of the cereal, but remember that sugar content isn’t the whole story. The cereal is more or less deficient in nutrients whereas oatmeal isn’t. Oatmeal is a complex carbohydrate.
As another example, if you had a banana and whole oats, no sugar, that meal would be obviously very healthy but nominally have 15 g of sugar.