CVE-2026-71290
Critical
Description
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.
SeverityCritical
CVSS9.1
Exploit probability—
Product
Apache Httpclient
PublishedAug 11, 2026
First seenAug 11, 2026
Weakness typeCWE-295CWE-295
How to fix
Update
- apache httpclient5.6.4 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| apache httpclient | 5.4 ≤ v < 5.6.4 | 5.6.4 |
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