Vulnerability in Apache Httpclient
CVE-2026-64607
HttpClient based on the classic i/o model fails to correctly release the underlying connection back to the connection manager if it encounters an invalid or unsupported `Content-Encoding` header value in the response message. Please note this defect does not affect HttpClient based on the async i/o model. This issue affects Apache HttpComponents Client: from 5.0-alpha1 through 5.6.2.
EPSS: 0.005 (40.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Apache Httpclient
- Apache Software Foundation Httpcomponents Client — versions 5.0-alpha
Weakness classification (CWE)
References
- security@apache.org (vendor-advisory, Mailing List, Release Notes)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-64607?
- CVE-2026-64607 is a medium-severity vulnerability in Apache Httpclient, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 5.3/10. Published 2026-07-31.
- How severe is CVE-2026-64607?
- Medium severity. CVSS v3 base score is 5.3 out of 10.