ENISA - European Network and Information Security Agency, the agency that drives Information Security among the EU Institutions and Member States has identified and reported various HTML5 security weaknesses. The report issued by ENISA is aimed at improving HTML specs before they are finalized. In all, the security evaluation of the new web standards by ENISA exposed 50 security threats and issues. The agency took the opportunity to come up with possible remedies to fix some issues and improvements to enhance the browser security.
To read the full report and get an insight of the new web standards go here.