Apache POI in versions prior to release 3.17 are vulnerable to Denial of Service Attacks: 1) Infinite Loops while parsing crafted WMF, EMF, MSG and macros (POI bugs 61338 and 61294), and 2) Out of Memory Exceptions while parsing crafted DOC, PPT and XLS (POI bugs 52372 and 61295).
https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
https://www.oracle.com/security-alerts/cpuoct2020.html
https://www.oracle.com/security-alerts/cpujul2020.html
https://www.oracle.com/security-alerts/cpujan2021.html
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.oracle.com/security-alerts/cpuapr2020.html
https://www.oracle.com/security-alerts/cpuApr2021.html