CVE-2026-405427.3HighCWE-304

CVE-2026-40542: Apache HttpClient: SCRAM-SHA-256 mutual authentication bypass may cause the client to accept authentication without proper mutual authentication verification

Apache Software Foundation · Apache HttpClient

Vendor fix available · Affected: Apache Software Foundation Apache HttpClient · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

45th percentile

050100

Higher than 45% of scored CVEs

7.3HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Apache Software Foundation · Apache HttpClientfrom 5.6 before 5.6.1

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Missing Critical Step in Authentication · Authentication
Vendor: Apache Software Foundation
Published: April 2026
Band: Unlikely (under 1%), April 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-40542 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

4 more references are in the CVE record.