---
id: CVE-2026-71290
title: "Improper TLS hostname verification vulnerability in Apache HttpComponents Client 5.4 or newer.\_HostnameVerificationPolicy#BUILTIN setting has no effect when used with the async version of HttpClient"
summary: "Improper TLS hostname verification vulnerability in Apache HttpComponents Client 5.4 or newer.\_HostnameVerificationPolicy#BUILTIN setting has no effect when used with the async version of HttpClient. An attacker that can intercept and mo…"
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-295
vendor: apache
product: httpclient
affected:
  - 'httpclient >= 5.4, < 5.6.4'
patched:
  - httpclient 5.6.4
published: '2026-08-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T04:17:48.873'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71290'
references:
  - url: 'https://lists.apache.org/thread/bhf7g2zwpom2ohvwjjjlonc93br2s8vq'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/08/13/6'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-23T00:00:00+00:00'
epss: 0.00331
epssPercentile: 0.23478
ingestedAt: '2026-09-24T04:38:03.276Z'
---

## Overview

Improper TLS hostname verification vulnerability in Apache HttpComponents Client 5.4 or newer. HostnameVerificationPolicy#BUILTIN setting has no effect when used with the async version of HttpClient. An attacker that can intercept and modify traffic between the client and the server can impersonate the server by presenting a valid certificate for a different domain. 


Please note the classic version of HttpClient is not affected by this vulnerability. 

Affected users are recommended to upgrade to at least version 5.6.4, which fixes the issue.

## Affected

- `httpclient >= 5.4, < 5.6.4`

## Remediation

Upgrade past the affected range:

- `httpclient 5.6.4`