Researchers at the University of Michigan and MIT found that an online voting platform already being used in some states has serious vulnerabilities, which could be exploited to alter votes without voters or elections officials noticing.
https://www.businessinsider.com/online-voting-system-can-be-hacked-to-alter-votes-report-2020-6
https://www.businessinsider.com/online-voting-system-can-be-hacked-to-alter-votes-report-2020-6