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.

Score

CVSS 3.1 5.3 Medium

Status

Modified - security@apache.org

Published

2026-07-31

Last modified

2026-10-23

Weaknesses

CWE-772

Affected products

• Httpclient (Apache)
• Apache Httpcomponents Client (Apache Software Foundation)

References

• https://lists.apache.org/thread/qqfzo3fqcdk4l5496vz95ppvl4ty511q
• http://www.openwall.com/lists/oss-security/2026/08/13/5