CVE-2026-40542
Apache HttpClient accepts SCRAM-SHA-256 authentication without proper mutual authentication verification
7.3
HIGH
CVSS 3.1
EPSS 0.05%
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.
How to fix CVE-2026-40542
To remediate CVE-2026-40542, upgrade the affected package to a fixed version below.
- —upgrade to 5.6.1 or later
Is CVE-2026-40542 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 5.6-alpha1, < 5.6.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |