CVE-2026-83525: Apache Kafka: Incorrect boolean operator in FetchSnapshot RPC handler allows authenticated network clients to crash the KRaft controller via a malformed request.

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-28 · updated 2026-10-29
Weakness: CWE-480

Description

Incorrect operator (CWE-480) in the FetchSnapshot RPC handler in Apache Kafka from 2.8.0 before 4.2.2, and from 4.3.0 before 4.3.2 on all platforms allows an authenticated attacker with CLUSTER_ACTION privilege to cause a denial of service (controller process termination) via a crafted FetchSnapshotRequest with an empty topics array or a topic with no partitions. Users are recommended to upgrade to version 4.2.2, 4.3.2, or 4.4.0, which fix this issue. Users on unsupported branches (4.1.x and earlier) should upgrade to 4.2.2 or later.

Affected products

Apache Kafka: from 2.8.0 before 4.2.2; from 4.3.0 before 4.3.2 — fixed in 4.2.2, 4.3.2

How to fix

Upgrade to a fixed version: Apache Kafka 4.2.2, 4.3.2. Check the vendor advisory for mitigations.

References

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