Findings

CVE-2026-35554

A race condition in the Apache Kafka Java producer client’s buffer pool management can cause messages to be silently delivered to incorrect topics.

Published Apr 7, 2026 · updated Aug 17, 2026 · apache kafka

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.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 7, 2026 · NIST NVD

    Detected

    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 dest

  2. Aug 17, 2026 · NIST NVD

    Updated

    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 dest

Affected

  • cpe apache/kafkaversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-35554

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-35554

    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

    nvd.nist.gov

References