---
title: "CVE-2026-102253: iperf3 - Denial of Service"
description: "iperf3 < 3.22 contains a denial of service vulnerability caused by crafted control-channel parameter messages and UDP datagrams, letting unauthenticated remote attackers crash the server's UDP receive worker into an infinite loop, exploit requires sending specific crafted messages."
url: https://panop.io/threat-heartbeat/CVE-2026-102253/
---

# CVE-2026-102253 iperf3 - Denial of Service

iperf3 < 3.22 contains a denial of service vulnerability caused by crafted control-channel parameter messages and UDP datagrams, letting unauthenticated remote attackers crash the server's UDP receive worker into an infinite loop, exploit requires sending specific crafted messages.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

Proof of concept available

Authentication

Not required

EPSS

0.43% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102253)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

29 September 2026

Updated

15 October 2026

Weakness

[CWE-835](https://cwe.mitre.org/data/definitions/835.html)

## Vendor fix

Update to version 3.22 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-102253](https://nvd.nist.gov/vuln/detail/CVE-2026-102253)
- [https://github.com/esnet/iperf/blob/master/RELNOTES.md](https://github.com/esnet/iperf/blob/master/RELNOTES.md)
- [https://github.com/esnet/iperf/releases/tag/3.22](https://github.com/esnet/iperf/releases/tag/3.22)
- [https://www.vulncheck.com/advisories/iperf3-udp-receive-worker-infinite-loop-dos](https://www.vulncheck.com/advisories/iperf3-udp-receive-worker-infinite-loop-dos)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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