GitHub has addressed the issue of session hijacking and mixed-content warnings on its website by implementing a solution that ensures secure embedding of images via GitHub flavored markdown. Previously, some pages allowed embedding images that resulted in mixed-content warnings, distracting users and compromising their sense of security. The solution involves rewriting the src attribute of img tags to proxy through GitHub's secure asset servers, thus eliminating the warnings. This technical change was executed by developing a simple HTTP proxy in Node.js, integrated with GitHub’s existing nginx setup. Users are encouraged to report any remaining issues through support tickets, as the new system appears to be functioning well. The company is now focusing on further feature development after resolving this security concern.