Zimbra Collaboration Suite uncheck cross-site scripting vulnerability

Synacor Zimbra Collaboration Suite (ZCS) is an open source collaboration suite from Synacor, Inc. A cross-site scripting vulnerability exists in Zimbra Collaboration Suite version 8.8.15, which stems from the lack of effective filtering and escaping of user-supplied data in the uncheck parameter in /h/calendar, which could be exploited to inject JavaScript code.