The IncomingMailServers resource in Atlassian JIRA Server before version 7.6.7, from version 7.7.0 before version 7.7.5, from version 7.8.0 before version 7.8.5, from version 7.9.0 before version 7.9.3 and from version 7.10.0 before version 7.10.2 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the messagesThreshold parameter as the fix for CVE-2017-18039 was incomplete.