geminabox (aka Gem in a Box) before 0.13.6 has XSS, as demonstrated by uploading a gem file that has a crafted gem.homepage value in its .gemspec file.
{ "versions": [ { "introduced": "0" }, { "last_affected": "0.13.5" } ] }
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2017-14506.json"