Collabora Online is a collaborative online office suite based on LibreOffice. A stored cross-site scripting vulnerability was found in Collabora Online. An attacker could create a document with an XSS payload in document text referenced by field which, if hovered over to produce a tooltip, could be executed by the user's browser. Users should upgrade to Collabora Online 23.05.10.1 or higher. Earlier series of Collabora Online, 22.04, 21.11, etc. are unaffected.