Fact-checking Mullin's claim that foreign adversaries can access voting machines in U.S. elections

By — Loreben Tuquero, PolitiFact Loreben Tuquero, PolitiFact Leave your feedback Share Copy URL https://www.pbs.org/newshour/politics/fact-checking-mullins-claim-that-foreign-adversaries-can-access-voting-machines-in-u-s-elections Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter Fact-checking Mullin's claim that foreign adversaries can access voting machines in U.S. elections Politics Jul 25, 2026 8:00 AM EDT This article originally appeared on PolitiFact . Department of Homeland Security Secretary Markwayne Mullin recently said, in unequivocal terms, that foreign adversaries can access voting machines and flip votes, echoing President Donald Trump's narrative about interference in the 2020 election. WATCH: Mullin holds news conference on election security after Trump's address to the nation "We know for sure that our foreign adversaries, not our allies, foreign adversaries have parts that are vital pieces in our voting machines," Mullin said July 17, adding that they can access "what they consider the key to the back" of the voting machines. "We know that they can change voter registration and your vote. We know it's possible. There's not a question. It's not even for debate." We asked the Department of Homeland Security for more details but it did not give any; it reiterated its call for states to help guard against noncitizen voters. The White House referred us to that department. (Noncitizen voting in federal elections is rare .) Educate your inbox Subscribe to Here’s the Deal, our politics newsletter for analysis you won’t find anywhere else. The process of registering to vote does not involve voting machines. But Mullin's comments about voting machines reflect concerns that security and election technology experts have long had. Voting machines have weaknesses that can allow foreign adversaries to tamper with voting machine hardware and weaken the machines' security, said J. Alex Halderman, University of Michigan computer science and engineering professor who studies electronic voting machines. Hardware attacks would allow foreign actors to manipulate the machines' security controls. But so far, there's no proof of such attempts. "It's important to note that there's no evidence that voting machine vulnerabilities have ever been used to attack a real U.S. election, and of course the existence of vulnerabilities does not mean those vulnerabilities will imminently be exploited," Halderman told PolitiFact via email. WATCH: Former intelligence official weighs Trump's election security allegations The U.S. Senate Select Committee on Intelligence noted these risks in a 2019 report on Russian interference in the 2016 election. The report said that in an experiment at a security conference, participants were able to hack into voting machines to change votes, install software and perform other unauthorized functions. But this was possible in part because the hackers were given physical access to the machines. Under