CVE-2026-40542
Received Received - Intake
Authentication Bypass in Apache HttpClient 5.6 via SCRAM-SHA

Publication date: 2026-04-22

Last updated on: 2026-05-01

Assigner: Apache Software Foundation

Description
Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version 5.6.1, which fixes this issue.
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Meta Information
Published
2026-04-22
Last Modified
2026-05-01
Generated
2026-06-16
AI Q&A
2026-04-22
EPSS Evaluated
2026-06-14
NVD
CVE-2026-40542
EUVD
EUVD-2026-24630
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
apache httpclient 5.6
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-304 The product implements an authentication technique, but it skips a step that weakens the technique.
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Executive Summary

This vulnerability is a missing critical step in the authentication process in Apache HttpClient version 5.6. It allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification.

This means that the client may trust an authentication attempt that has not been fully verified, potentially allowing unauthorized access.

Users are recommended to upgrade to version 5.6.1, which fixes this issue.

Impact Analysis

This vulnerability can impact you by allowing an attacker to bypass proper mutual authentication verification when using Apache HttpClient 5.6 with SCRAM-SHA-256 authentication.

As a result, an attacker could potentially impersonate a legitimate server or client, leading to unauthorized access or data interception.

Mitigation Strategies

Users are recommended to upgrade Apache HttpClient to version 5.6.1, which fixes the authentication issue allowing acceptance of SCRAM-SHA-256 without proper mutual authentication verification.

Compliance Impact

The provided information does not specify how the vulnerability in Apache HttpClient 5.6 impacts compliance with common standards and regulations such as GDPR or HIPAA.

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