An issue was discovered in the gon gem before gon-6.4.0 for Ruby. MultiJson does not honor the escape_mode parameter to escape fields as an XSS protection mechanism. To mitigate, json_dumper.rb in gon now does escaping for XSS by default without relying on MultiJson.
https://usn.ubuntu.com/4560-1/
https://lists.debian.org/debian-lts-announce/2020/09/msg00018.html
https://github.com/gazay/gon/commit/fe3c7b2191a992386dc9edd37de5447a4e809bc7