Python versions 3.3 through 3.5 suffer from a vulnerability caused by the behavior of the product_setstate() function. When called, the function loops over the state tuple provided and clamps each given index to a value within a range from 0 up to the max number of pools. Then, it loops over the pools and gets an item from the pool using the previously clamped index value. However, for the upper bound, the clamping logic is using the number of pools and not the size of the individual pool, which can result in a call to PyTuple_GET_ITEM that uses an index outside of the bounds of the pool.