5 ozs of corn sugar = 11 gravity points. In 5 gallons that would be about 2 points per gallon. or the equivalent of changing the .002. This would equate to about 0.25%.
But ..... it all depends on how much water you dissolve it in. If you dissolve it in 2 pints, the added priming liquid will have a gravity of 1.044, and if used in a beer that had an OG of 1.044 would result in zero increase in abv. (Yes, I know corn sugar will ferment out to lower than 1.000, so would actually add some extra abv, but not enough to argue about).
By the same rationale, if the 2 pints of priming liquid was added to a high gravity beer, it might slightly reduce the final abv.