CVE-2023-28366: Eclipse Mosquitto

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

The broker in Eclipse Mosquitto 1.3.2 through 2.x before 2.0.16 has a memory leak that can be abused remotely when a client sends many QoS 2 messages with duplicate message IDs, and fails to respond to PUBREC commands. This occurs because of mishandling of EAGAIN from the libc send function.

Affected products

• Eclipse Mosquitto: from 1.3.2, before 2.0.16 (fixed in 2.0.16)

Published 2023-09-01. Last modified 2026-06-17.