CVE-2026-40542
Apache HttpClient: SCRAM-SHA-256 mutual authentication bypass may cause the client to accept authentication without proper mutual authentication verification
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.
INFO
Published Date :
April 22, 2026, 8:16 a.m.
Last Modified :
May 1, 2026, 5:12 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Upgrade Apache HttpClient to version 5.6.1.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40542.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97 | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/04/22/5 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40542 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40542
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40542 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40542 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 01, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:httpclient:5.6:-:*:*:*:*:*:* Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/22/5 Types: Mailing List, Third Party Advisory Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97 Types: Mailing List, Vendor Advisory -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Apr. 22, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/04/22/5 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 22, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L -
New CVE Received by [email protected]
Apr. 22, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-304 Added Reference https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97