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HIGHFixed upstream

CVE-2026-35554

race condition in the Apache Kafka Java producer client’s buffer pool management can cause…

Technology

Apache Kafka

CVSS Score

8.7 / 10.0

Affected Versions

>=2.8.0 <3.9.2; >=4.0.0 <4.0.2; >=4.1.0 <4.1.2

Upstream Fix

See upstream advisory

Published

April 7, 2026

OSSeva Coverage

Fixed upstream

Description

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 prod

Is your Apache Kafka deployment affected?

If you're running >=2.8.0 <3.9.2; >=4.0.0 <4.0.2; >=4.1.0 <4.1.2, you need this patch. Book a discovery call to get covered.