Vulnerability record · CVE-2013-4366 · published 30 October 2017

CVE-2013-4366: Apache httpclient improper input validation vulnerability

Apache · Httpclient

http/impl/client/HttpClientBuilder.java in Apache HttpClient 4.3.x before 4.3.1 does not ensure that X509HostnameVerifier is not null, which allows attackers to have unspecified impact via vectors involving hostname verification.

9.8 CVSS 3.1 Critical EPSS 3.3% · top 11.9% CWE-20 · Improper input validation

9.8CVSS 3.1 base score, v2 7.5

3.3%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

4References

16 Jun 2026Last modified by NVD

Description

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Httpclient Apache

References

Link	Tags
http://svn.apache.org/r1528614	Issue TrackingPatchRelease NotesVendor Advisory
http://www.apache.org/dist/httpcomponents/httpclient/RELEASE_NOTES-4.3.x.txt	Issue TrackingRelease NotesVendor Advisory
http://svn.apache.org/r1528614	Issue TrackingPatchRelease NotesVendor Advisory
http://www.apache.org/dist/httpcomponents/httpclient/RELEASE_NOTES-4.3.x.txt	Issue TrackingRelease NotesVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2013-4366), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.