The XML Validator used by cyclonedx-core-java was not configured securely, making the library vulnerable to XML External Entity (XXE) injection. The fix for GHSA-683x-4444-jxh8 / CVE-2024-38374 has been incomplete in that it only fixed parsing of XML BOMs, but not validation.
Before deserializing CycloneDX Bill of Materials in XML format, cyclonedx-core-java leverages XPath expressions to determine the schema version of the BOM. The DocumentBuilderFactory used to evaluate XPath expressions was not configured securely, making the library vulnerable to XML External Entity (XXE) injection. XXE injection can be exploited to exfiltrate local file content, or perform Server Side Request Forgery (SSRF) to access infrastructure adjacent to the vulnerable application.