Apache CXF before 3.3.4 and 3.2.11 does not restrict the number of message attachments present in a given message. This leaves open the possibility of a denial of service type attack, where a malicious user crafts a message containing a very large number of message attachments. From the 3.3.4 and 3.2.11 releases, a default limit of 50 message attachments is enforced. This is configurable via the message property "attachment-max-count".