Description
A flaw was found in iperf3. A remote attacker can exploit this vulnerability by sending crafted control-channel JSON with oversized numeric parameters, such as `parallel` and `len`, which are not properly validated by the server. This improper input validation can lead to excessive stream and thread creation, as well as large buffer allocations, causing resource exhaustion. Consequently, this can result in a Denial of Service (DoS) on the affected iperf3 server.
Published: 2026-08-11
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Workaround

To mitigate this issue, restrict network access to the `iperf3` server to trusted clients or networks using firewall rules. If the `iperf3` server functionality is not required, disable the `iperf3` service.

Tracking

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Advisories

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History

Tue, 11 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Tue, 11 Aug 2026 10:30:00 +0000


Tue, 11 Aug 2026 09:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in iperf3. A remote attacker can exploit this vulnerability by sending crafted control-channel JSON with oversized numeric parameters, such as `parallel` and `len`, which are not properly validated by the server. This improper input validation can lead to excessive stream and thread creation, as well as large buffer allocations, causing resource exhaustion. Consequently, this can result in a Denial of Service (DoS) on the affected iperf3 server.
Title Iperf3: iperf3 server accepts unbounded peer-controlled json parameters enabling remote denial of service via resource exhaustion
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-20
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Subscriptions

Redhat Enterprise Linux
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-08-11T10:19:45.209Z

Reserved: 2026-08-05T08:41:54.899Z

Link: CVE-2026-71217

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-11T09:17:14.057

Modified: 2026-08-11T11:17:16.397

Link: CVE-2026-71217

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-11T08:13:48Z

Links: CVE-2026-71217 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-11T10:30:04Z

Weaknesses