https://www.cnet.com/news/shutdown-government-sites-with-lapsed-security-certificates-pose-risk/

If the shutdown drags on, more certificates are likely to expire, because they can require employees to renew them. As a result, "[T]here could be some realistic opportunities to undermine the security of all US citizens," Paul Mutton, a security researcher at Netcraft, wrote in a company blog post Thursday.

Netcraft's findings underscore the toll taken on US government cybersecurity by the protracted shutdown, which has left hundreds of thousands of federal employees and contractors furloughed.