What’s Vulnerable › Vulnerabilities

CVE-2023-28366

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-09-01 · updated 2026-06-17
• Weakness: CWE-401

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.

Affected products

• The Eclipse Foundation Eclipse Mosquitto: from 1.3.2 before 2.0.16 — fixed in 2.0.16

How to fix

Upgrade to a fixed version: The Eclipse Foundation Eclipse Mosquitto 2.0.16. Check the vendor advisory for mitigations.

References

• https://github.com/eclipse/mosquitto/commit/6113eac95a9df634fbc858be542c4a0456bfe7b9
• https://github.com/eclipse/mosquitto/compare/v2.0.15...v2.0.16
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJ2FMBGVVQEQWTTQB7YLKTAHMX2UM66X/
• https://mosquitto.org/blog/2023/08/version-2-0-16-released/
• 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
• https://www.debian.org/security/2023/dsa-5511
• https://github.com/eclipse/mosquitto/commit/6113eac95a9df634fbc858be542c4a0456bfe7b9
• https://github.com/eclipse/mosquitto/compare/v2.0.15...v2.0.16
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KJ2FMBGVVQEQWTTQB7YLKTAHMX2UM66X/
• https://mosquitto.org/blog/2023/08/version-2-0-16-released/
• https://security.gentoo.org/glsa/202401-09

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