Apache Kafka 4.1.0 JWT Token improper authentication

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
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5.4$0-$5k3.67

Summaryinfo

A vulnerability labeled as critical has been found in Apache Kafka 4.1.0. The impacted element is an unknown function of the component JWT Token Handler. Such manipulation leads to improper authentication. This vulnerability is documented as CVE-2026-33557. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apache Kafka 4.1.0. It has been rated as critical. Affected by this issue is an unknown part of the component JWT Token Handler. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability.

The advisory is available at lists.apache.org. This vulnerability is handled as CVE-2026-33557. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 04/17/2026).

Upgrading to version 4.1.2 or 4.2.0 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kafka 4.1.2/4.2.0

Timelineinfo

04/17/2026 Advisory disclosed
04/17/2026 +0 days VulDB entry created
04/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apache.org

Advisory: lists.apache.org
Status: Confirmed

CVE: CVE-2026-33557 (🔒)
GCVE (CVE): GCVE-0-2026-33557
GCVE (VulDB): GCVE-100-358046

Entryinfo

Created: 04/17/2026 10:55
Changes: 04/17/2026 10:55 (52)
Complete: 🔍
Cache ID: 216::103

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