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Vulnerability · Published Aug 11, 2026 · Assigned by redhat

CVE-2026-71218Iperf3: unbounded peer-controlled allocation in iperf3 json_read() allows unauthenticated remote memory exhaustion

Medium 5.3

In plain English

A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.4%top 67.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12iperf3no fix listedDEBIAN-CVE-2026-71218
Debian:13iperf33.18-1DEBIAN-CVE-2026-71218
Debian:14iperf33.18-1DEBIAN-CVE-2026-71218

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references

Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References