CVE-2026-35554

Описание

A race condition in the Apache Kafka Java producer client’s buffer pool management can cause messages to be silently delivered to incorrect topics. When a produce batch expires due to delivery.timeout.ms while a network request containing that batch is still in flight, the batch’s ByteBuffer is prematurely deallocated and returned to the buffer pool. If a subsequent producer batch—potentially destined for a different topic—reuses this freed buffer before the original network request completes, the buffer contents may become corrupted. This can result in messages being delivered to unintended topics without any error being reported to the producer. Data Confidentiality: Messages intended for one topic may be delivered to a different topic, potentially exposing sensitive data to consumers who have access to the destination topic but not the intended source topic. Data Integrity: Consumers on the receiving topic may encounter unexpected or incompatible messages, leading to deserialization failures, processing errors, and corrupted downstream data. This issue affects Apache Kafka versions ≤ 3.9.1, ≤ 4.0.1, and  ≤ 4.1.1. Kafka users are advised to upgrade to 3.9.2, 4.0.2, 4.1.2, 4.2.0, or later to address this vulnerability.

A flaw was found in the Apache Kafka Java producer client. A race condition in the client's buffer pool management can cause messages to be silently delivered to incorrect topics. This occurs when a message batch expires while its network request is still active, leading to premature buffer deallocation and potential reuse by other messages. Consequently, sensitive data may be exposed to unauthorized consumers, and data integrity can be compromised through deserialization failures and processing errors.