The upstream patch for CVE-2014-8080 introduced checks against the REXML.entity_expansion_text_limit, but did not add restrictions to limit the number of expansions performed, i.e. checks against the REXML::Document.entity_expansion_limit. As a consequence, even with the patch applied, a small XML document could cause REXML to use an excessive amount of CPU time. High memory usage can be achieved using larger inputs.