JIRA allows the entry of invalid UNICODE characters in description and comment, but these create invalid XML strings in the rss feeds

Copying and pasting into JIRA allows pasting of values below hex 32 other than the permitted values. When output in the RSS feed these are escaped with their appropriate values e.g.  but this is invalid in XML as it is not permitted as a unicode character. It makes my XML parser (MSXML 2.0) fall over with the message "Invalid UNICODE Character" when parsing the XML version of the issue in RSS.