TLS hostname verification when using the Apache ActiveMQ Client before 5.15.6 was missing which could make the client vulnerable to a MITM attack between a Java application using the ActiveMQ client and the ActiveMQ server. This is now enabled by default.

Spring Framework, versions 5.0.x prior to 5.0.7 and 4.3.x prior to 4.3.18 and older unsupported versions, allows web applications to enable cross-domain requests via JSONP (JSON with Padding) through AbstractJsonpResponseBodyAdvice for REST controllers and MappingJackson2JsonView for browser requests. Both are not enabled by default in Spring Framework nor Spring Boot, however, when MappingJackson2JsonView is configured in an application, JSONP support is automatically ready to use through the "jsonp" and "callback" JSONP parameters, enabling cross-domain requests.

Spring Framework, versions 5.0.x prior to 5.0.6, versions 4.3.x prior to 4.3.17, and older unsupported versions allows applications to expose STOMP over WebSocket endpoints with a simple, in-memory STOMP broker through the spring-messaging module. A malicious user (or attacker) can craft a message to the broker that can lead to a regular expression, denial of service attack.