No one has charged ballot box stuffing. The only complaint the United States has voiced regarding these and previous elections is the for in which candidates are chosen for the highest offices. The U.S. coverage of the electoral system usually ignores the content of the electoral process. The fact is that all local, district, and provincial delegates are chosen by standard electoral models used the world over. There must be two or more candidates, whom anyone can nominate at open public meetings.
People can even nominate themselves.
There is universal suffrage for those who are 16 years and older, with no racial, gender, religious, or political discrimination. There is a secret ballot. These elected delegates in turn appoint an electoral commission of individuals selected by civic, social, trade union, women's, student and political organizations. It's the electoral commission's job to carry out a massive grassroots selection process to represent the broadest cross-section of the Cuban population in a slate of candidates for the higher offices of the National Assembly. In this year's elections, the electoral commission analyzed over 60,000 proposals, discussing them with over a million voters, individually and through their civic social, political, and trade union organizations, in order to come up with the final, non-partisan slate.