XXE in the XML parser library in RealObjects PDFreactor before 10.1.10722 allows attackers to supply malicious XML content in externally referenced resources, leading to disclosure of local file contents and/or denial of service conditions.
https://www.pdfreactor.com/pdfreactor-10-maintenance-release-10-1-10722-now-available/
https://www.pdfreactor.com/important-pdfreactor-security-advisory/
https://blog.gdssecurity.com/labs/2019/5/28/ssrf-and-xxe-vulnerabilities-in-pdfreactor.html