An issue was discovered in the Calendar feature in Zimbra Collaboration Suite 8.8.x before 8.8.15 patch 30 (update 1), as exploited in the wild starting in December 2021. An attacker could place HTML containing executable JavaScript inside element attributes. This markup becomes unescaped, causing arbitrary markup to be injected into the document.
A reflected cross-site scripting (XSS) vulnerability in the /public/launchNewWindow.jsp component of Zimbra Collaboration (aka ZCS) 9.0 allows unauthenticated attackers to execute arbitrary web script or HTML via request parameters.