Apache HttpClient: SCRAM-SHA-256 mutual authentication bypass may cause the client to accept authentication without proper mutual authentication verification
Summary
| CVE | CVE-2026-40542 |
|---|---|
| State | PUBLISHED |
| Assigner | apache |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-22 08:16:12 UTC |
| Updated | 2026-06-30 03:19:18 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.3 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS: 0.004560000 probability, percentile 0.364140000 (date 2026-07-02)
Problem Types: CWE-304 | CWE-325 | CWE-304 CWE-304: Missing Critical Step in Authentication | CWE-325 Missing Cryptographic Step
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | ADP | CVSS | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Apache | Httpclient | 5.6 | - | All | All |
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.openwall.com/lists/oss-security/2026/04/22/5 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | Mailing List, Third Party Advisory |
| access.redhat.com/security/cve/CVE-2026-40542 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97 | [email protected] | lists.apache.org | Mailing List, Vendor Advisory |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40542.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Rasmus Moorats (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-04-22T08:00:57.407Z | Reported to Red Hat. |
| ADP | 2026-04-22T07:07:21.344Z | Made public. |
There are currently no legacy QID mappings associated with this CVE.