Apache XmlSchema doesn't limit how deeply schema structures can be nested when it builds its schema model, so a malicious schema can make parsing recurse until the stack overflows. This causes a denial of service.
Users are recommended to upgrade to version 2.3.3, which fixes this issue.
The Apache XmlSchema walker (xmlschema-walker) doesn't detect cycles in type derivation, substitution groups, model groups or attribute groups. A malicious schema with such a cycle can make the walker recurse until the stack overflows, causing a denial of service.
Users are recommended to upgrade to version 2.3.3, which fixes this issue.