A single ScriptEngine instance is reused for every message on a script-backed channel. For JSR-223 engines that report THREADING=null (not thread-safe, e.g. the Kotlin kts engine), concurrent message processing can corrupt engine-internal state, potentially leaking one message's payload/headers bindings into another message's script evaluation or throwing spurious exceptions.
Spring Integration 7.1.0
Spring Integration 7.0.0 - 7.0.5
Spring Integration 6.5.0 - 6.5.10
Spring Integration 6.4.0 - 6.4.12
Spring Integration 5.5.21 and earlier
The EmbeddedHeadersJsonMessageMapper defaults to an overly permissive header parsing posture in its constructor. When decodeNativeFormat processes raw byte payloads, it deserializes embedded JSON headers into a plain Map and constructs a GenericMessage with MutableMessageHeaders without sanitizing or filtering untrusted header names by default.
Spring Integration 7.1.0
Spring Integration 7.0.0 - 7.0.5
Spring Integration 6.5.0 - 6.5.10
Spring Integration 6.4.0 - 6.4.12
Spring Integration 5.5.21 and earlier
When an IntegrationFlow uses .fluxTransform() with an asynchronous/reordering fluxFunction that emits raw payloads, concurrent requests on the same FluxMessageChannel subscription have their reply headers (replyChannel, errorChannel, correlationId, any propagated security/tenant headers) copied from whichever message was most recently consumed upstream.
Spring Integration 7.1.0
Spring Integration 7.0.0 - 7.0.5
Spring Integration 6.5.0 - 6.5.10
Spring Integration 6.4.0 - 6.4.12
Spring Integration 5.5.21 and earlier
Spring Integration (spring-integration-xml and spring-integration-ws modules), versions 4.3.18, 5.0.10, 5.1.1, and older unsupported versions, were susceptible to XML External Entity Injection (XXE) when receiving XML data from untrusted sources.