unsafe deserialization in hyphenation loading vulnerability in Apache XML Graphics FOP. This issue affects Apache XML Graphics FOP: through 2.11. Users are recommended to upgrade to version 2.12, which fixes the issue.
https://lists.apache.org/thread.html/nsb89to1r0vzdh3t4w7x10q4z3xk5jqf
https://issues.apache.org/jira/browse/FOP-3332