CVE-2026-102253
Description
A flaw was found in iperf3. An unauthenticated remote attacker can exploit this issue by sending a crafted control-channel message followed by a specific User Datagram Protocol (UDP) datagram to the server. This causes the UDP receive processing thread to enter an unrecoverable infinite loop, leading to sustained high CPU utilization and a Denial of Service (DoS) condition.
Statement
This vulnerability is rated as Important severity for Red Hat because an unauthenticated remote attacker can trigger complete denial of service through severe CPU resource exhaustion without requiring elevated privileges. While iperf3 is predominantly invoked on demand for diagnostic network throughput benchmarking rather than deployed as a continuous background daemon, any active listener exposed to untrusted network traffic can be forced into an unresponsive state. The affected process ceases responding to control messages and requires manual administrative termination via SIGKILL, rendering benchmarking services unavailable.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
Frequently Asked Questions
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