CVE-2026-44367
Deferred Deferred - Pending Action
Inconsistent Username Handling Causes DoS in Klaw

Publication date: 2026-06-02

Last updated on: 2026-06-02

Assigner: GitHub, Inc.

Description
Klaw is a self-service Apache Kafka Topic Management/Governance tool/portal. Prior to version 2.10.4, a vulnerability exists in the user registration and login mechanisms due to inconsistent handling of username case sensitivity, leading to a targeted Denial of Service (DoS) and complete account lockout. This issue has been patched in version 2.10.4.
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Meta Information
Published
2026-06-02
Last Modified
2026-06-02
Generated
2026-06-23
AI Q&A
2026-06-02
EPSS Evaluated
2026-06-21
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
aiven klaw to 2.10.4 (exc)
Helpful Resources
Exploitability
CWE
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KEV
KEV Icon
CWE ID Description
CWE-20 The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-178 The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.
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Executive Summary

The vulnerability exists in Klaw versions 2.10.3 and earlier in the user registration and login mechanisms due to inconsistent handling of username case sensitivity.

Specifically, the registration process uses case-sensitive validation, while the login process uses case-insensitive lookups. This discrepancy allows an attacker to register a username with different casing (for example, "victiM" when "victim" already exists).

This creates two conflicting accounts that become inaccessible to both users and breaks administrative tools, leading to a targeted Denial of Service (DoS) and complete account lockout.

The issue was fixed in version 2.10.4 by enforcing case-insensitive username handling.

Impact Analysis

This vulnerability can impact you by causing a Denial of Service (DoS) through account lockout.

An attacker can exploit the inconsistent case sensitivity to create conflicting user accounts that lock out legitimate users, including administrators.

This results in loss of access to affected accounts and breaks administrative tools, potentially disrupting management and governance of Kafka topics.

There are no workarounds; upgrading to version 2.10.4 is necessary to prevent future occurrences, and administrators must manually resolve existing locked accounts by editing the database.

Detection Guidance

This vulnerability involves inconsistent case sensitivity handling in user registration and login, leading to conflicting accounts with different username casing that cause account lockout.

Detection involves identifying duplicate usernames that differ only in letter casing (e.g., "victiM" vs "victim") in the Klaw user database.

Since the issue is related to database entries, you can detect it by querying the user table for usernames that are duplicates ignoring case.

  • Run a SQL query to find usernames differing only by case, for example (syntax may vary depending on your database):
  • SELECT LOWER(username), COUNT(*) FROM users GROUP BY LOWER(username) HAVING COUNT(*) > 1;

No specific network commands or logs are mentioned for detection, as the vulnerability is at the application and database level.

Mitigation Strategies

The primary mitigation is to upgrade Klaw to version 2.10.4 or later, where the vulnerability is fixed by enforcing case-insensitive username handling.

Since the application interface cannot delete duplicate locked accounts, administrators must manually resolve existing locked accounts by editing the database to remove or merge conflicting usernames.

No workarounds exist other than upgrading and manual database cleanup.

Compliance Impact

The provided information does not include any details on how this vulnerability affects compliance with common standards and regulations such as GDPR or HIPAA.

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