In Redmine before 3.2.6 and 3.3.x before 3.3.3, stored XSS is possible by using an SVG document as an attachment.
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "3.4.2-1", "binary_name": "redmine" }, { "binary_version": "3.4.2-1", "binary_name": "redmine-mysql" }, { "binary_version": "3.4.2-1", "binary_name": "redmine-pgsql" }, { "binary_version": "3.4.2-1", "binary_name": "redmine-sqlite" } ] }