iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS (CVE-2026-102253) | HOL Guard CVE

High · CVSS 8.7CVE-2026-102253

iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS

Answer in brief

CVE-2026-102253 records a High severity (CVSS 8.7) vulnerability in iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS. The current sources do not mark it as known exploited. The current feed maps esnet/iperf3 (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 29, 2026Updated Sep 29, 2026Source checked Sep 29, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps esnet/iperf3 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
esnet/iperf3generic	>=3.14 <3.22	3.22

Recommended response

Check inventory. Check lockfiles and deployed manifests for esnet/iperf3.
Review the reported fix. Update esnet/iperf3 to 3.22 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.