CVE-2026-41726 In Spring for Apache Kafka, unbounded delegate cache keyed on user-controlled, potentially malicious selector header

When an application opts into DelegatingDeserializer, a producer can grow the consumer's heap without bound by sending records with unique random spring.kafka.serialization.selector header values, eventually causing GC thrash and OutOfMemoryError. Affected versions: Spring for Apache Kafka 4.0.0...