Cross-site scripting (XSS) vulnerability in the frontend in Open-Xchange (OX) AppSuite 7.4.1 before 7.4.1-rev10 and 7.4.2 before 7.4.2-rev8 allows remote attackers to inject arbitrary web script or HTML via the subject of an email, involving 'the aria "tags" for screenreaders at the top bar'.