In the rcfilters plugin 2.1.6 for Roundcube, XSS exists via the _whatfilter and _messages parameters (in the Filters section of the settings).
{ "versions": [ { "introduced": "0" }, { "last_affected": "2.1.6" } ] }
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-16736.json"