MEDIUM

CVE-2026-64607

Apache HttpComponents Client: Connection Leak on Content-Encoding Decode Error Leads to Pool Exhaustion DoS

CVSS v3

5.3

MEDIUM

EPSS Score

0.5 %

exploit probability, as of 2026-10-17

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

org.apache.httpcomponents.client5:httpclient5Mavenfrom 5.0-alpha1 · fixed in 5.6.3

Vendor advisories

CVE-2026-64607 Red Hat Product Security42 products fixed · 14 known affected
org.apache.httpcomponents.client5/httpclient5: Apache HttpComponents Client: Denial of Service due to connection leak
openshift-serverless-1/kn-eventing-integrations-aws-ddb-streams-source-rhel9 as a component of OpenShift Serverless · openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9 as a component of OpenShift Serverless · openshift-serverless-1/kn-eventing-integrations-aws-s3-source-rhel9 as a component of OpenShift Serverless
RHSA-2026:83612 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat build of Debezium 3.6.3 release
RHSA-2026:71675 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat Build of Apache Camel 4.18.4 for Spring Boot release.
RHSA-2026:63302 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat Build of Apache Camel 4.18 for Quarkus 3.33 update is now available (RHBQ 3.33.3.SP1)
RHSA-2026:62515 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat build of Quarkus 3.27.5.SP1 release and security update
RHSA-2026:60259 Red Hat Product Security4 products fixed
Red Hat Security Advisory: Release of Red Hat OpenShift Developer Tools - Openshift Jenkins 4.20 security update.

10 more advisories

Full record on NVD

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published: 2026-07-31
Last Modified: 2026-07-31

Frequently asked questions

What is CVE-2026-64607?

Is CVE-2026-64607 actively exploited?

Active exploitation of CVE-2026-64607 has not been confirmed. Its EPSS score was 0.5% on 2026-10-17, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-64607?

CVE-2026-64607 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

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