CVE-2026-35554
HighCVSS 8.7Exploitation Probability (EPSS)
Low risk38th percentile - higher than 38% of all known CVEs
Summary
A race condition in the Apache Kafka Java producer client's buffer pool management can cause messages to be silently delivered to incorrect topics. The issue is fixed in newer versions.
Risk Assessment
Data confidentiality may be breached (messages go to unintended consumers) and data integrity may be compromised (corrupted downstream data).
Recommendation
Upgrade Apache Kafka to version 3.9.2, 4.0.2, 4.1.2, 4.2.0 or later.
Other vulnerabilities in Apache Kafka
See all- CVE-2026-33557Critical
In Apache Kafka, the default JWT validator class (`DefaultJwtValidator`) accepts any JWT token without validating its signature, issuer, or audience. An attacker can generate a token from any issuer with any username, and the broker will accept it.
- CVE-2026-41115Medium
An improper authorization vulnerability has been identified in Apache Kafka. The CONSUMER_GROUP_DESCRIBE (69) API validates the DESCRIBE operation on the GROUP resource instead of the READ operation as documented. This can result in misconfigured ACLs and unintended security postures.
Original NVD description (English source)
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.