---
id: CVE-2026-85058
title: Moquette is a lightweight Java MQTT broker
summary: >-
  Moquette is a lightweight Java MQTT broker. Prior to 0.18.1,
  PostOffice.publishWill publishes a client-controlled Last Will message through
  publish2Subscribers without invoking the authorizator.canWrite check used by
  normal PUBLISH paths…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-862
vendor: moquette
product: 'io.moquette:moquette-broker'
affected:
  - 'io.moquette:moquette-broker < 0.18.1'
patched:
  - 'io.moquette:moquette-broker 0.18.1'
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85058'
references:
  - url: >-
      https://github.com/moquette-io/moquette/commit/e23df019f6a11e22c7d2047d4f86d07095466c97
    label: security-advisories@github.com
  - url: >-
      https://github.com/moquette-io/moquette/commit/f5a323fe782d1505c0097498cb22eb6ec6c96973
    label: security-advisories@github.com
  - url: 'https://github.com/moquette-io/moquette/releases/tag/v0.18.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/moquette-io/moquette/security/advisories/GHSA-9jjc-fw8x-fmwx
    label: security-advisories@github.com
  - url: >-
      https://github.com/moquette-io/moquette/security/advisories/GHSA-9jjc-fw8x-fmwx
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-9jjc-fw8x-fmwx'
tags:
  - nvd
  - ghsa
  - maven
  - cve.org
  - exploit-available
epss: 0.00451
epssPercentile: 0.36559
aliases:
  - GHSA-9jjc-fw8x-fmwx
ecosystem: maven
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-22T15:13:17.846630Z'
ingestedAt: '2026-09-18T17:46:41.535Z'
---

## Overview

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, PostOffice.publishWill publishes a client-controlled Last Will message through publish2Subscribers without invoking the authorizator.canWrite check used by normal PUBLISH paths. When anonymous access is enabled and topic ACLs restrict writes, a remote client can set an ACL-protected topic as the Last Will Topic during CONNECT and perform an abnormal client disconnect, causing the broker to inject attacker-controlled messages into a topic for which the client lacks write permission. This issue is fixed in version 0.18.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-85058)

Affected packages:

- `io.moquette:moquette-broker < 0.18.1`

Patched in:

- `io.moquette:moquette-broker 0.18.1`

Source: https://github.com/advisories/GHSA-9jjc-fw8x-fmwx