A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service.
History

Tue, 11 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Iperf3 Project
Iperf3 Project iperf3
Vendors & Products Iperf3 Project
Iperf3 Project iperf3

Tue, 11 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 11 Aug 2026 10:45:00 +0000


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

Type Values Removed Values Added
Description A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service.
Title Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-789
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': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-08-11T13:00:19.528Z

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

Link: CVE-2026-71218

cve-icon Vulnrichment

Updated: 2026-08-11T13:00:14.163Z

cve-icon NVD

Status : Received

Published: 2026-08-11T09:17:14.200

Modified: 2026-08-11T14:17:14.967

Link: CVE-2026-71218

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-11T08:13:07Z

Links: CVE-2026-71218 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-11T14:19:40Z