A DESCRIPTION OF THE PROBLEM :
If a fatal error occurs, XMLStreamReader/XMLEventReader prints "Fatal Error" to stderr, and there is no way to disable this logging.

StaxErrorReporting is overriding XMLErrorReporter.reportError(XMLLocator,String,String,Object[],short), but it seems like it should be overriding reportError(...,Exception).

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Catch and ignore all exceptions from XMLEventReader.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No output printed to stderr.
ACTUAL -
The following is printed to stderr:
[Fatal Error] :-1:-1: Invalid byte 1 of 1-byte UTF-8 sequence.

---------- BEGIN SOURCE ----------
import java.io.ByteArrayInputStream;
import javax.xml.stream.XMLInputFactory;
public class InputByteTest {
  public static void main(String[] args) {
    var in = new ByteArrayInputStream(new byte[] { (byte) 0xff });
    try {
      XMLInputFactory.newInstance().createXMLEventReader(in).next();
    } catch (Throwable t) {}
  }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None.