Vulnerability · Published Sep 29, 2026 · Assigned by VulnCheck
CVE-2026-102253iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS
High 7.5
In plain English
A high-severity infinite loop in iperf3 from esnet. 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 37% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
iperf3 versions prior to 3.22 contains a denial of service vulnerability that allows unauthenticated remote attackers to crash-loop the server's UDP receive worker into an unrecoverable infinite loop by sending a single crafted control-channel parameter message followed by one 16-byte UDP datagram. Attackers can permanently pin the affected per-stream receive thread at approximately 100% CPU usage, rendering the server unusable until forcibly killed with SIGKILL, as the process does not respond to normal control-channel closure.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | iperf3 | 3.17.1-6.el10_2.2 | ALSA-2026:88207 |
| Debian:13 | iperf3 | no fix listed | DEBIAN-CVE-2026-102253 |
| Debian:14 | iperf3 | 3.22-0.1 | DEBIAN-CVE-2026-102253 |
| Rocky Linux:10 | iperf3 | 0:3.17.1-6.el10_2.2 | RLSA-2026:88207 |
| Ubuntu:26.04:LTS | iperf3 | no fix listed | UBUNTU-CVE-2026-102253 |
| Ubuntu:26.10 | iperf3 | no fix listed | UBUNTU-CVE-2026-102253 |
Affected products (as reported)
Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- Vendor Patch vendor-advisory, patch
- Vendor Release Notes release-notes
- VulnCheck Advisory third-party-advisory