XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Versions 10.4-rc-1, through 16.10.15, 17.0.0-rc-1, through 17.4.7 and 17.5.0-rc-1 through 17.10.0 contain a reflected cross-site scripting vulnerability (XSS) in the comparison view between revisions of a page allows executing JavaScript code in the user's browser. If the current user is an admin, this can not only affect the current user but also the confidentiality, integrity and availability of the whole XWiki instance. If developers are unable to update immediately, they can apply the patch manually to templates/changesdoc.vm in the deployed WAR.