It was found that spring security uses Jackson's enableDefaultTyping() polymorphic capability for object deserialization. Jackson has already addressed this issue by blacklisting well-known gadget classes. However, under a right circumstances (e.g. an existence of an old JDK and vulnerable Jackson in classpath), an attacker could use this vulnerability to craft a malicious payload which would be deserialized by Jackson via spring security. This execution could potentially lead to remote code execution on the target machine.