# CVE-2021-38153: Observable Discrepancy in Apache Kafka

Source: https://junglewise.ai/threats/cve-2021-38153-observable-discrepancy-in-apache-kafka  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-09-23  
License: CC BY 4.0 with a link back

CVE-2021-38153 · Severity: low · CVSS 3.1 · Published 2021-09-23

Observable Discrepancy in Apache Kafka

Technologies: [org.apache.kafka:kafka_2.11 (Maven)](https://junglewise.ai/threats/technologies/org-apache-kafka-kafka-2-11), [org.apache.kafka:kafka_2.12 (Maven)](https://junglewise.ai/threats/technologies/org-apache-kafka-kafka-2-12), [org.apache.kafka:kafka_2.13 (Maven)](https://junglewise.ai/threats/technologies/org-apache-kafka-kafka-2-13), [org.apache.kafka:kafka-clients (Maven)](https://junglewise.ai/threats/technologies/org-apache-kafka-kafka-clients). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2021-38153 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-38153 being exploited in the wild.

**How severe is CVE-2021-38153?** Low severity, with a CVSS score of 3.1, published 23 September 2021.

**Which products and versions are affected?** org.apache.kafka:kafka_2.11 (Maven) ECOSYSTEM:introduced=2.0.0,last_affected=2.4.1; org.apache.kafka:kafka_2.12 (Maven) ECOSYSTEM:introduced=2.0.0,fixed=2.6.3; org.apache.kafka:kafka_2.13 (Maven) ECOSYSTEM:introduced=2.4.0,fixed=2.6.3; org.apache.kafka:kafka-clients (Maven) ECOSYSTEM:introduced=2.0.0,fixed=2.6.3.

**Is there a fix for CVE-2021-38153?** Yes. org.apache.kafka:kafka_2.12 (Maven): upgrade to 2.6.3 or later; org.apache.kafka:kafka_2.13 (Maven): upgrade to 2.6.3 or later; org.apache.kafka:kafka-clients (Maven): upgrade to 2.6.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-38153?** Check whether you run org.apache.kafka:kafka_2.11 (Maven), org.apache.kafka:kafka_2.12 (Maven), org.apache.kafka:kafka_2.13 (Maven) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.apache.kafka:kafka_2.12 (Maven): upgrade to 2.6.3 or later

  ```sh
  # set org.apache.kafka:kafka_2.12 to 2.6.3 in your pom.xml or build.gradle
  ```

- org.apache.kafka:kafka_2.13 (Maven): upgrade to 2.6.3 or later

  ```sh
  # set org.apache.kafka:kafka_2.13 to 2.6.3 in your pom.xml or build.gradle
  ```

- org.apache.kafka:kafka-clients (Maven): upgrade to 2.6.3 or later

  ```sh
  # set org.apache.kafka:kafka-clients to 2.6.3 in your pom.xml or build.gradle
  ```


## Affected products

- org.apache.kafka:kafka_2.11 (Maven) ECOSYSTEM:introduced=2.0.0,last_affected=2.4.1
- org.apache.kafka:kafka_2.12 (Maven) ECOSYSTEM:introduced=2.0.0,fixed=2.6.3
- org.apache.kafka:kafka_2.13 (Maven) ECOSYSTEM:introduced=2.4.0,fixed=2.6.3
- org.apache.kafka:kafka-clients (Maven) ECOSYSTEM:introduced=2.0.0,fixed=2.6.3

## Identifiers

- CVE-2021-38153
- GHSA-3j6g-hxx5-3q26

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- [Apache Kafka Kafka Clients race condition in Kafka Producer](https://junglewise.ai/threats/cve-2026-35554-apache-kafka-kafka-clients-race-condition-in-kafka-producer)
- [Apache Kafka Client Arbitrary File Read and Server Side Request Forgery Vulnerability](https://junglewise.ai/threats/cve-2025-27817-apache-kafka-client-arbitrary-file-read-and-server-side-request)
- [Apache Kafka Deserialization of Untrusted Data vulnerability](https://junglewise.ai/threats/cve-2025-27819-apache-kafka-deserialization-of-untrusted-data-vulnerability)