GHSA-5QCV-4RPC-JP93
Vulnerability from github – Published: 2026-04-07 15:30 – Updated: 2026-04-13 19:22A 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.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.kafka:kafka-clients"
},
"ranges": [
{
"events": [
{
"introduced": "2.8.0"
},
{
"fixed": "3.9.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.kafka:kafka-clients"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.0.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.kafka:kafka-clients"
},
"ranges": [
{
"events": [
{
"introduced": "4.1.0"
},
{
"fixed": "4.1.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-35554"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-13T19:22:21Z",
"nvd_published_at": "2026-04-07T14:16:23Z",
"severity": "HIGH"
},
"details": "A race condition in the Apache Kafka Java producer client\u2019s buffer pool management can cause messages to be silently delivered to incorrect topics.\n\nWhen a produce batch expires due to delivery.timeout.ms while a network request containing that batch is still in flight, the batch\u2019s ByteBuffer is prematurely deallocated and returned to the buffer pool. If a subsequent producer batch\u2014potentially destined for a different topic\u2014reuses 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.\n\n\nData Confidentiality:\nMessages 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.\n\nData Integrity:\nConsumers on the receiving topic may encounter unexpected or incompatible messages, leading to deserialization failures, processing errors, and corrupted downstream data.\n\nThis issue affects Apache Kafka versions \u2264 3.9.1, \u2264 4.0.1, and\u00a0 \u2264 4.1.1.\n\nKafka users are advised to upgrade to 3.9.2, 4.0.2, 4.1.2, 4.2.0, or later to address this vulnerability.",
"id": "GHSA-5qcv-4rpc-jp93",
"modified": "2026-04-13T19:22:21Z",
"published": "2026-04-07T15:30:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-35554"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/pull/21065"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/pull/21285"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/pull/21286"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/pull/21287"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/pull/21288"
},
{
"type": "WEB",
"url": "https://github.com/apache/kafka/commit/1df2ac5b2ba4d1b5ed54b895ff6fb9539303ccb5"
},
{
"type": "PACKAGE",
"url": "https://github.com/apache/kafka"
},
{
"type": "WEB",
"url": "https://issues.apache.org/jira/browse/KAFKA-19012"
},
{
"type": "WEB",
"url": "https://lists.apache.org/thread/f07x7j8ovyqhjd1to25jsnqbm6wj01d6"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2026/04/07/6"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Apache Kafka Clients: Kafka Producer Message Corruption and Misrouting via Buffer Pool Race Condition"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.