CVE-2026-102253: esnet iperf3 · Infinite Loop
Affects esnet iperf3Source CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to 3.22 soon.
Data as of 13 Nov 2026, 12:10 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.7 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.5 |
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.22
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade esnet iperf3 to 3.22.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| esnetiperf3 | Affected
| Fixed in
|
GitHubiperf3pkg:github/iperf3Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade iperf3 to version 3.22 or later, where this vulnerability is fixed. No other mitigations are indicated or required.
Description
iperf3 versions from 3.14 up to but not including 3.22 contain a denial of service vulnerability that allows unauthenticated remote attackers to cause an infinite loop in the server's UDP receive worker. This results in the affected per-stream receive thread consuming approximately 100% CPU indefinitely, making the server unresponsive until forcibly terminated. The vulnerability is fixed in version 3.22.