Solr uses a really old version (3.2.7) of the Woddstox API, the current stable version being 4.4.1.
This old version is packaged in the same jar with an equally old version of StAX2 API. This makes it difficult to update just the StAX API with a more recent version - in my application I ran into this when trying to use StAXON.
I propose to update to Woodstox 4.4.1 and StAX2 3.1.4.
SOLR-5064 Update <dependency org="org.codehaus.woodstox" name="wstx-asl" rev="3.2.7" transitive="false"/> to a more recent version.