The CMS server generates XML documents in a variety of circumstances, however it always omits the critically import xml declaration entity. The XML rfc's suggest the declaration should always be included. In particular it is critically important because the xml declaration declares the document encoding. The xml documents should be preceded by something like this:

<?xml version="1.0" encoding="UTF-8"?>

I have not verified that all text being output by CMS is in fact encoded in UTF-8, but it should be, and I assume it is.

The primary point is the receiver of the XML document should be able to parse an xml declaration and by virtue of that establish the xml version and document encoding.