CVE-2026-33558
Information exposure vulnerability has been identified in Apache Kafka.
Does this matter?
Lower severity and a low EPSS score (0.63%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 0.63% probability · 48th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-533
- Affected
- apache/kafka
- Source
- security@apache.org
References
- https://kafka.apache.org/cve-listVendor Advisory
- https://lists.apache.org/thread/pz5g4ky3h0k91tfd14p0dzqjp80960klMitigation, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2026/04/17/3Mailing List
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.