Is CVE-2026-33558 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-33558 being exploited in the wild.

How severe is CVE-2026-33558?

Medium severity, with a CVSS score of 5.3, published 20 April 2026.

Which products and versions are affected?

org.apache.kafka:kafka-clients (Maven) ECOSYSTEM:introduced=0.11.0,fixed=3.9.2.

Is there a fix for CVE-2026-33558?

Yes. org.apache.kafka:kafka-clients (Maven): upgrade to 3.9.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2026-33558?

Check whether you run Apache Kafka or org.apache.kafka:kafka-clients (Maven) 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.

CVE-2026-33558: Apache Kafka exposes sensitive information in its DEBUG logs

CVE-2026-33558 · Severity: medium · CVSS 5.3 · Published 2026-04-20

Information exposure vulnerability has been identified in Apache Kafka.

The NetworkClient component will output entire requests and responses information in the DEBUG log level in the logs. By default, the log level is set to INFO level. If the DEBUG level is enabled, the sensitive information will be exposed via the requests and responses output log. The entire lists of impacted requests and responses are:

* AlterConfigsRequest

* AlterUserScramCredentialsRequest

* ExpireDelegationTokenRequest

* IncrementalAlterConfigsRequest

* RenewDelegationTokenRequest

* SaslAuthenticateRequest

* createDelegationTokenResponse

* describeDelegationTokenResponse

* SaslAuthenticateResponse

This issue affects Apache Kafka: from any version supported the listed API above through v3.9.1, v4.0.0. We advise the Kafka users to upgrade to v3.9.2, v4.0.1, or later to avoid this vulnerability.

Technologies: Apache Kafka, org.apache.kafka:kafka-clients (Maven). Vendors: Apache, Maven.

Quick answers

Is CVE-2026-33558 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-33558 being exploited in the wild.
How severe is CVE-2026-33558?: Medium severity, with a CVSS score of 5.3, published 20 April 2026.
Which products and versions are affected?: org.apache.kafka:kafka-clients (Maven) ECOSYSTEM:introduced=0.11.0,fixed=3.9.2.
Is there a fix for CVE-2026-33558?: Yes. org.apache.kafka:kafka-clients (Maven): upgrade to 3.9.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-33558?: Check whether you run Apache Kafka or org.apache.kafka:kafka-clients (Maven) 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-clients (Maven): upgrade to 3.9.2 or later

# set org.apache.kafka:kafka-clients to 3.9.2 in your pom.xml or build.gradle

Affected products

Apache Kafka
org.apache.kafka:kafka-clients (Maven) ECOSYSTEM:introduced=0.11.0,fixed=3.9.2

Identifiers

CVE-2026-33558
GHSA-wf66-mphr-4c4r

References

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