A pre-authentication attacker could leverage unbounded symbol value caching to cause resource exhaustion leading to denial of service. This issue affects Apache Qpid Proton-J: through 0.34.1. Users are recommended to upgrade to version 0.35.0, which fixes the issue.
https://lists.apache.org/thread/dnczt6bgfcq2x6q8ljco177h1qmv59fm