Vulnerability in Apache Httpclient
CVE-2026-71290
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.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Apache Httpclient
- Apache Software Foundation Httpcomponents Client — versions 5.4-alpha
Weakness classification (CWE)
References
- lists.apache.org/thread/bhf7g2zwpom2ohvwjjjlonc93br2s8vq (vendor-advisory, Mailing List, Release Notes)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-71290?
- CVE-2026-71290 is a critical-severity vulnerability in Apache Httpclient, classified under Improper Certificate Validation. CVSS score: 9.1/10. Published 2026-08-11.
- How severe is CVE-2026-71290?
- Critical severity. CVSS v3 base score is 9.1 out of 10.