XStream before 1.4.14 is susceptible to remote code execution. An attacker can run arbitrary shell commands by manipulating the processed input stream, thereby making it possible to obtain sensitive information, modify data, and/or execute unauthorized administrative operations in the context of the affected site. Users who rely on blocklists are affected.
View the template here CVE-2020-26217.yaml
References:
https://lists.apache.org/thread.html/r2de526726e7f4db4a7cb91b7355070779f51a84fd985c6529c2f4e9e@%3Cissues.activemq.apache.org%3E