From https://metaculus.com/questions/17177/election-hack-before-2025/

Attacks on voting machines are becoming more common. In Dec 2022, the Brennan Center for Justice wrote that "In 2016, Russian hackers targeted election systems in all 50 states. No votes were actually changed, but the hackers penetrated at least Illinois’s database deeply enough to have the ability to delete or change voter data. Few election officials even noticed the digital incursions.

It couldn’t have been a particularly difficult mission for Russia’s army of hackers: Many U.S. voting machines were more than a decade old. Some were so outdated that officials had to buy spare parts on eBay. A few were running Windows 2000." In April 2023, it called for funding from DHS, CISA, EAC, and the FBI to direct more resources to combat these threats.

European countries have also expressed concerns, with the European Union Agency for Network and Information Security (ENISA) stating that "Core electoral systems are being targeted by digital communities, institutions, and actors." (pdf.

As of May 2023, no major attacks on voting systems have been directly attributable to AI.