What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-11 · updated 2026-08-14
• Weakness: CWE-789

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 products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 7: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-71218
• https://bugzilla.redhat.com/show_bug.cgi?id=2463003
• https://github.com/esnet/iperf/commit/0128d0357b7e8916fe39e980e455729bc0e5fd4e

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