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.
Published: 2026-04-20
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Sensitive Information Exposure via Log Files
Action: Patch
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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-wf66-mphr-4c4r Apache Kafka exposes sensitive information in its DEBUG logs
History

Wed, 22 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:apache:kafka:*:*:*:*:*:*:*:*
cpe:2.3:a:apache:kafka:4.0.0:-:*:*:*:*:*:*
cpe:2.3:a:apache:kafka:4.0.0:rc0:*:*:*:*:*:*
cpe:2.3:a:apache:kafka:4.0.0:rc1:*:*:*:*:*:*
cpe:2.3:a:apache:kafka:4.0.0:rc3:*:*:*:*:*:*

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache kafka
Apache kafka Clients
Vendors & Products Apache
Apache kafka
Apache kafka Clients

Mon, 20 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 20 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
References

Mon, 20 Apr 2026 14:00:00 +0000

Type Values Removed Values Added
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.
Title Apache Kafka, Apache Kafka Clients: Information Exposure Through Network Client Log Output
Weaknesses CWE-533
References

Subscriptions

Apache Kafka Kafka Clients
cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-04-20T14:20:41.640Z

Reserved: 2026-03-23T03:46:25.070Z

Link: CVE-2026-33558

cve-icon Vulnrichment

Updated: 2026-04-20T13:38:53.596Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-20T14:16:19.010

Modified: 2026-04-22T14:16:12.910

Link: CVE-2026-33558

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-22T11:48:08Z

Weaknesses