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NVD / CVE Program· CNA apache

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

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.63% (FIRST EPSS); higher than 50.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: org.apache.kafka:kafka-clients (Maven) 3.9.2, 4.0.1.

Low priority for now. Upgrade to org.apache.kafka:kafka-clients (Maven) 3.9.2, 4.0.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.3 · v3.1—No exploit Fix available
Published
Apr 20, 2026
Updated
Oct 26, 2026
EPSS
0.6% · 50th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
apachekafka

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache kafka0.11.0.0 and later · before 3.9.2
  • apache kafka4.0.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache Kafka

    • 4.0.0affected
    • 0.11.0 and later · up to and including 3.9.1affected · semver

  • Apache Software Foundation Apache Kafka Clients

    • 4.0.0affected
    • 0.11.0 and later · up to and including 3.9.1affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Mavenorg.apache.kafka:kafka-clientsfrom 0.11.0 · before 3.9.23.9.2
Mavenorg.apache.kafka:kafka-clientsfrom 4.0.0 · before 4.0.14.0.1

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-27817Apache Kafka Client: Arbitrary file read and SSRF vulnerability
    51Plan
  • CVE-2018-17196In Apache Kafka versions between 0.11.0.0 and 2.1.0, it is possible to manually craft a Produce request which bypasses transaction/idempoten
    37Monitor
  • CVE-2026-33557Apache Kafka: Missing JWT token validation in OAUTHBEARER authentication
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-27819Jun 10, 2025 · Apache Kafka: Possible RCE/Denial of service attack via SASL JAAS JndiLoginModule configuration
    30Monitor
  • ← EarlierCVE-2026-35554Apr 7, 2026 · Apache Kafka Clients: Kafka Producer Message Corruption and Misrouting via Buffer Pool Race Condition
    34Monitor
  • Later →CVE-2026-41115Jun 2, 2026 · Apache Kafka: Improper Authorization in CONSUMER_GROUP_DESCRIBE API
    17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Maven:org.apache.kafka:kafka-clients3.9.2Package registry (OSV)
Maven:org.apache.kafka:kafka-clients4.0.1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-533 · DEPRECATED: Information Exposure Through Server Log Files

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records