CVE-2023-31126: Improper Neutralization of Invalid Characters in Identifiers in Web Pages

org.xwiki.commons:xwiki-commons-xml is an XML library used by the open-source wiki platform XWiki. The HTML sanitizer, introduced in version 14.6-rc-1, allows the injection of arbitrary HTML code and thus cross-site scripting via invalid data attributes. This vulnerability does not affect restricted cleaning in HTMLCleaner as there attributes are cleaned and thus characters like / and > are removed in all attribute names. This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by making sure that data attributes only contain allowed characters. There are no known workarounds apart from upgrading to a version including the fix.