The Translate WordPress with GTranslate WordPress plugin before 3.0.10 does not validate one of its settings before the bundled front-end scripts build markup from it, allowing users with a role as high as administrator to store JavaScript that runs in the session of any visitor to the site.
https://wpscan.com/vulnerability/423b6be0-e0f2-42c0-8b40-4015e4a0e670/