CVE-2023-28366 — The broker in Eclipse Mosquitto 1
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 se
Published
2023-09-01T00:00:00.000Z
Last modified
2025-06-26T13:59:02.058Z
01What is this vulnerability?
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.
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2023-09-01T00:00:00.000Z
- Last modified: 2025-06-26T13:59:02.058Z
09References
- github.com — https://github.com/eclipse/mosquitto/compare/v2.0.15...v2.0.16
- www.compass-security.com — https://www.compass-security.com/fileadmin/Research/Advisories/2023_02_CSNC-2023…
- mosquitto.org — https://mosquitto.org/blog/2023/08/version-2-0-16-released/
- github.com — https://github.com/eclipse/mosquitto/commit/6113eac95a9df634fbc858be542c4a0456bf…
- lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
- www.debian.org — https://www.debian.org/security/2023/dsa-5511
- security.gentoo.org — https://security.gentoo.org/glsa/202401-09
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