script tags, embed tags, object tags, frameset tags, iframe tags, meta tags, link tags, style tags, style attributes from every tag.
If you are always subscribing to different blogs, forums and mailing lists through RSS, you should be careful about it. If there are comments RSS, you could also take precautionary measures by not subscribing to it. It is possible to get attacked through the RSS of comments. Aside from that, if you have set up your own personal aggregator, make sure that you have a ‘smart’ aggregator which strips off the said tags. If you have an aggregator on your computer, check if it is vulnerable. Maybe you could install something else that isn’t prone to attacks via RSS. It is better to be secure after all.