I wouldn't consider that a parsing vulnerability - XML is relatively easy to parse - but rather an XML processing vulnerability, as in you must disable certain

I wouldn't consider that a parsing vulnerability - XML is relatively easy to parse - but rather an XML processing vulnerability, as in you must disable certain features (like arbitrary filesystem access) when processing an untrusted document. With hindsight, an XML processing library should require that you turn features like that on, rather than require that you turn them off. Opt in to dangerous features rather than opt out of them in other words.