Message misrouting via premature buffer reuse
Published Apr 7, 2026 · Updated Apr 7, 2026
Race condition in Apache Kafka Clients 2.8.0 through 3.9.1, 4.0.0 through 4.0.1, and 4.1.0 through 4.1.1 allows attackers to misroute messages. An expiring producer batch returns its ByteBuffer to the pool while the network request still references it, so a later batch can overwrite in-flight contents. Triggering requires batch expiration under delivery.timeout.ms, an in-flight request, and buffer reuse before completion; unintended consumers can receive or fail to parse the corrupted message.
Summary
What happened
Race condition in Apache Kafka Clients 2.8.0 through 3.9.1, 4.0.0 through 4.0.1, and 4.1.0 through 4.1.1 allows attackers to misroute messages. An expiring producer batch returns its ByteBuffer to the pool while the network request still references it, so a later batch can overwrite in-flight contents. Triggering requires batch expiration under delivery.timeout.ms, an in-flight request, and buffer reuse before completion; unintended consumers can receive or fail to parse the corrupted message.
The record
- CVE
- CVE-2026-35554
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Kafka Clients
- Classifications
- CWE-416, CWE-362
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.8.0 <=3.9.1
- Affected versionversion=4.0.0 <=4.0.1
- Affected versionversion=4.1.0 <=4.1.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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