0.0
NA
CVE-2026-64607
Apache HttpComponents Client: Connection Leak on Content-Encoding Decode Error Leads to Pool Exhaustion DoS
Description

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.

INFO

Published Date :

July 31, 2026, 11:17 a.m.

Last Modified :

July 31, 2026, 11:17 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-64607 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update HttpClient to a version that correctly handles invalid Content-Encoding headers.
  • Update Apache HttpComponents Client to version 5.7 or later.
  • Ensure response encoding is handled correctly.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-64607.

URL Resource
https://lists.apache.org/thread/qqfzo3fqcdk4l5496vz95ppvl4ty511q
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-64607 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-64607 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-64607 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-64607 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 31, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Apache Software Foundation', 'product': 'Apache HttpComponents Client', 'versions': [{'status': 'affected', 'version': '5.0-alpha', 'versionType': 'semver', 'lessThanOrEqual': '5.6.2'}], 'packageName': 'org.apache.httpcomponents.client5:httpclient5', 'collectionURL': 'https://repo.maven.apache.org/maven2/', 'defaultStatus': 'unaffected'}]
    Added Description 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.
    Added CWE CWE-772
    Added Reference https://lists.apache.org/thread/qqfzo3fqcdk4l5496vz95ppvl4ty511q
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.