# DSA-5511-1: mosquitto security update

DSA-5511-1, released October 1, 2023, fixes 1 CVE in mosquitto. None of them is reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/fix/linux/dsa-5511-1
- Platform: Linux
- Released: Oct 1, 2023
- Priority: Routine (Closes CVE-2021-34434)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://security-tracker.debian.org/tracker/CVE-2021-34434

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [mosquitto](https://patchblox.com/security/data/product/linux/mosquitto.md) | Debian 11.6 (bullseye) | 2.0.11-1+deb11u1 |
| [mosquitto](https://patchblox.com/security/data/product/linux/mosquitto.md) | Debian 12.15 (bookworm) | 2.0.11-1.2+deb12u1 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-34434](https://patchblox.com/security/data/cve/CVE-2021-34434.md) | Routine | mosquitto: mosquitto - security update | n/a | 0.0133 |  |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo