# CVE-2023-5632: mosquitto: In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending dat...

CVE-2023-5632 is fixed in mosquitto on 1 platform, first by DEBIAN-CVE-2023-5632, released October 18, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-5632
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0080
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 18, 2023

## Description

In Eclipse Mosquito before and including 2.0.5, establishing a connection to the mosquitto server without sending data causes the EPOLLOUT event to be added, which results excessive CPU consumption. This could be used by a malicious actor to perform denial of service type attack. This issue is fixed in 2.0.6

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mosquitto Debian 12.15 (bookworm) | 2.0.7-1 | [DEBIAN-CVE-2023-5632](https://patchblox.com/security/data/fix/linux/debian-cve-2023-5632.md) | Oct 18, 2023 |
| Linux | mosquitto Debian 13.5 (trixie) | 2.0.7-1 | [DEBIAN-CVE-2023-5632](https://patchblox.com/security/data/fix/linux/debian-cve-2023-5632.md) | Oct 18, 2023 |
| Linux | mosquitto Debian 14 | 2.0.7-1 | [DEBIAN-CVE-2023-5632](https://patchblox.com/security/data/fix/linux/debian-cve-2023-5632.md) | Oct 18, 2023 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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