CVE-2026-33558

CVE-2026-33558: Apache Kafka, Apache Kafka Clients: Information Exposure Through Network Client Log Output

Vendor Apache Software Foundation
Product Apache Kafka
Weakness CWE-533
Published April 20, 2026
Last update April 20, 2026

CVSS base score

What the vulnerability does

Description

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.

Key dates

Disclosure timeline

April 20, 2026 CVE published
April 20, 2026 Record updated