Axigen Mail Server before 10.5.69, 10.6.x before 10.6.40, and 10.7.x before 10.7.2 contains an unauthenticated denial of service vulnerability caused by unbounded nesting depth when parsing SOAP/XML and JSON request bodies before authentication. Attackers can send a single deeply nested request to WebMail, WebAdmin, or WebMail Proxy listeners to exhaust the stack and crash SMTP, IMAP, POP3, and web services repeatedly.