CVE-2026-102253: Esnet IPERF3

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Esnet IPERF3: from 3.14, before 3.22 (fixed in 3.22)

Published 2026-09-29. Last modified 2026-09-30.