Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Remotely triggered via a single malformed response header (AV:N/AC:L/PR:N/UI:N); impact is a bounded connection-pool leak affecting only availability, so C:N/I:N and A:L rather than A:H.
Primary rating from Vendor (apache).
CVSS VectorVendor: apache
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Lifecycle Timeline
3Blast Radius
ecosystem impact- 6 maven packages depend on org.apache.httpcomponents.client5:httpclient5 (6 direct, 0 indirect)
Ecosystem-wide dependent count for version 5.0-alpha1.
DescriptionCVE.org
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.
AnalysisAI
Denial of service in Apache HttpComponents Client (versions 5.0-alpha1 through 5.6.2) arises when the classic/blocking I/O HttpClient fails to release the underlying connection back to the pool after receiving a response carrying an invalid or unsupported Content-Encoding header. An attacker who controls or can influence the server a client talks to can repeatedly return such headers to leak connections until the pool is exhausted, halting further outbound HTTP requests from the affected Java application. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Requires the application to use the classic (blocking) I/O HttpClient - the async I/O HttpClient is explicitly not vulnerable - on a version between 5.0-alpha1 and 5.6.2, and requires the client to receive HTTP responses containing an invalid or unsupported Content-Encoding header value, which means the attacker must control or influence a server the client connects to (malicious upstream, MITM, or attacker-reachable/SSRF target). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | No CVSS vector, EPSS score, KEV entry, or POC was provided, so severity must be inferred from the description and CWE-772. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A Java service using the classic HttpComponents Client to call an external API is pointed (via configuration, SSRF, or a compromised/malicious upstream) at a server the attacker controls. The server answers each request with a response bearing a bogus Content-Encoding value; every such response leaks a pooled connection, and after enough requests the connection manager is exhausted and the service can no longer make outbound HTTP calls, causing a denial of service. … |
| Remediation | Upgrade Apache HttpComponents Client to the fixed release above 5.6.2 as directed by the Apache advisory at https://lists.apache.org/thread/qqfzo3fqcdk4l5496vz95ppvl4ty511q; a released patched version could not be independently confirmed from the provided data, so consult that advisory for the exact fix version rather than relying on an assumed number. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all Java applications using Apache HttpComponents Client versions 5.0-alpha1 through 5.6.2 and assess which systems make outbound HTTP requests to external or partially-trusted servers. …
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More in Apache Httpcomponents Client
View allSame technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: Moderate| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| openSUSE Leap 16.0 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5 | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Manager Proxy 4.3 | Affected |
| SUSE Manager Retail Branch Server 4.3 | Affected |
| SUSE Manager Server 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE Manager Server Module 4.3 | Affected |
| SUSE Enterprise Storage 7 | Affected |
| SUSE Enterprise Storage 7.1 | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP2 | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3 | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy 4.1 | Affected |
| SUSE Manager Proxy 4.2 | Affected |
| SUSE Manager Retail Branch Server 4.1 | Affected |
| SUSE Manager Retail Branch Server 4.2 | Affected |
| SUSE Manager Server 4.1 | Affected |
| SUSE Manager Server 4.2 | Affected |
| SUSE Manager Server Module 4.2 | Affected |
| openSUSE Leap 15.3 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
| bci/openjdk-devel bci/openjdk-devel:11 bci/openjdk-devel:17 bci/openjdk-devel:21 containers/apache-pulsar:3.3 suse/manager/5.0/x86_64/server suse/multi-linux-manager/5.1/x86_64/server suse/multi-linux-manager/5.2/x86_64/server | Affected |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-51519
GHSA-hjcp-jmpx-g3qm