The state of California has put together an extensive plan to review every voting system in use in the state. The work will use several groups of indepedent scientists with excellent credentials who will review both electronic voting systems and other, older voting systems, including paper-based balloting.
The state is serious about this; the plan includes the use of independent "red teams" that will work independently to try to break into the electronic systems. This is not likely to be very difficult, since you can go right to YouTube and watch a short video on how to break into some systems.
The tragedy here is that this kind of analysis and review should have been done before California spent a half billion tax dollars buying untested voting equipment. State and local officials in California and in every other state ignored the pleas of computer scientists and technology experts across the country and blindly wasted billions buying flawed equipment. Most of it will end up being replaced.
The good news: at least the problem is getting fixed before a massive vote fraud creats a constitutional crisis in a major election. Let's hope every state addresses this issue promptly.