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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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.
    (CVE-2026-35554)

An update of the kafka package has been released.

ID	Name	Product	Family	Type	Severity
457255	Echo: org.apache.kafka:kafka-clients: security update to 3.9.2	Tenable Cloud Security	Echo Local Security Checks	Local	high
457255	Echo: org.apache.kafka:kafka-clients: security update to 3.9.2	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
333640	Photon OS 5.0: Kafka PHSA-2026-5.0-91-0855	Nessus	PhotonOS Local Security Checks	Local	high
317381	Photon OS 5.0: Kafka PHSA-2026-5.0-0855	Nessus	PhotonOS Local Security Checks	Local	high

Detections

Analytics

CVE-2026-35554

high

Tenable Plugins

high

high

high

high