CVE-2026-33558
Published:April 20, 2026
Updated:April 23, 2026
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.
Affected Packages
org.apache.kafka:kafka-clients (JAVA):
Affected version(s) =4.0.0 <4.0.1Fix Suggestion:
Update to version 4.0.1org.apache.kafka:kafka-clients (JAVA):
Affected version(s) >=0.11.0.0 <3.9.2Fix Suggestion:
Update to version 3.9.2Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
EPSS
Base Score:
0.03
