A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service. This issue affects Apache Qpid ProtonJ2: through 1.1.0. Users are recommended to upgrade to version 1.2.0, which fixes the issue.
https://lists.apache.org/thread/kmov6k7f3moqy01m1s370fl61vgos3ly