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Vulnerability record · CVE-2023-28366 · published 1 September 2023

CVE-2023-28366: Eclipse mosquitto memory leak vulnerability

Eclipse · Mosquitto

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.

7.5 CVSS 3.1 High EPSS 1.3% · top 30.3% CWE-401 · Memory leak
7.5CVSS 3.1 base score
1.3%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
14References
17 Jun 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/eclipse/mosquitto/commit/6113eac95a9df634fbc858be542c4a0456bfe7b9 Patch
https://github.com/eclipse/mosquitto/compare/v2.0.15...v2.0.16 Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJ2FMBGVVQEQWTTQB7YLKTA
https://mosquitto.org/blog/2023/08/version-2-0-16-released/ Release Notes
https://security.gentoo.org/glsa/202401-09
https://www.compass-security.com/fileadmin/Research/Advisories/2023_02_CSNC-2023-001_Eclipse_Mosquitto_Memory_Leak.txt Third Party Advisory
https://www.debian.org/security/2023/dsa-5511
https://github.com/eclipse/mosquitto/commit/6113eac95a9df634fbc858be542c4a0456bfe7b9 Patch
https://github.com/eclipse/mosquitto/compare/v2.0.15...v2.0.16 Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJ2FMBGVVQEQWTTQB7YLKTA
https://mosquitto.org/blog/2023/08/version-2-0-16-released/ Release Notes
https://security.gentoo.org/glsa/202401-09
https://www.compass-security.com/fileadmin/Research/Advisories/2023_02_CSNC-2023-001_Eclipse_Mosquitto_Memory_Leak.txt Third Party Advisory
https://www.debian.org/security/2023/dsa-5511

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.1CVE-2018-12550Eclipse mosquitto vulnerabilityWhen Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comments or bl…EPSS 1.4%8.1CVE-2018-12551Eclipse mosquitto improper authentication vulnerabilityWhen Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the password f…EPSS 1.5%7.5CVE-2023-5632Eclipse mosquitto vulnerabilityIn Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data causes the EPOLLOUT event to b…EPSS 0.69%7.5CVE-2023-3592Eclipse mosquitto memory leak vulnerabilityIn Mosquitto before 2.0.16, a memory leak occurs when clients send v5 CONNECT packets with a will message that contains invalid property types.EPSS 0.79%7.5CVE-2021-41039Eclipse mosquitto vulnerabilityIn versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CP…EPSS 1.4%7.5CVE-2021-34432Eclipse mosquitto improper input validation vulnerabilityIn Eclipse Mosquitto versions 2.0.7 and earlier, the server will crash if the client tries to send a PUBLISH packet with topic length = 0.EPSS 1.2%7.5CVE-2017-7655Eclipse mosquitto null pointer dereference vulnerabilityIn Eclipse Mosquitto version from 1.0 to 1.4.15, a Null Dereference vulnerability was found in the Mosquitto library which could lead to crashes for …EPSS 1.8%7.5CVE-2018-20145Eclipse mosquitto incorrect permission assignment vulnerabilityEclipse Mosquitto 1.5.x before 1.5.5 allows ACL bypass: if the option per_listener_settings was set to true, and the default listener was in use, and…EPSS 1.6%

Source: NIST National Vulnerability Database (record CVE-2023-28366), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.