# CVE-2017-7653: libmosquitto1: The Eclipse Mosquitto broker up to version 1.4.15 does not reject strings that are not valid UTF-8

CVE-2017-7653 is fixed in 4 products on 1 platform, first by libmosquitto1 1.4.15-2ubuntu0.18.04.3, released June 4, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2017-7653
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0144
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 4, 2018

## Description

The Eclipse Mosquitto broker up to version 1.4.15 does not reject strings that are not valid UTF-8. A malicious client could cause other clients that do reject invalid UTF-8 strings to disconnect themselves from the broker by sending a topic string which is not valid UTF-8, and so cause a denial of service for the clients.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libmosquitto1 Ubuntu 18.04.6 LTS (bionic) | 1.4.15-2ubuntu0.18.04.3 | [libmosquitto1 1.4.15-2ubuntu0.18.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libmosquitto1-1.4.15-2ubuntu0.18.04.3.md) | Jun 4, 2018 |
| Linux | libmosquittopp1 Ubuntu 18.04.6 LTS (bionic) | 1.4.15-2ubuntu0.18.04.3 | [libmosquittopp1 1.4.15-2ubuntu0.18.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libmosquittopp1-1.4.15-2ubuntu0.18.04.3.md) | Jun 4, 2018 |
| Linux | mosquitto Ubuntu 18.04.6 LTS (bionic) | 1.4.15-2ubuntu0.18.04.3 | [mosquitto 1.4.15-2ubuntu0.18.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-mosquitto-1.4.15-2ubuntu0.18.04.3.md) | Jun 4, 2018 |
| Linux | mosquitto-clients Ubuntu 18.04.6 LTS (bionic) | 1.4.15-2ubuntu0.18.04.3 | [mosquitto-clients 1.4.15-2ubuntu0.18.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-mosquitto-clients-1.4.15-2ubuntu0.18.04.3.md) | Jun 4, 2018 |

---

Data as of 2026-11-07T06:34:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo