---
id: CVE-2026-95843
title: Moquette is a lightweight Java MQTT broker
summary: >-
  Moquette is a lightweight Java MQTT broker. Prior to 0.18.1,
  PostOffice.subscribe parses a shared-subscription filter through
  SharedSubscriptionUtils.extractShareName before validating the complete
  $share/{shareName}/{topicFilter} struct…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-20
vendor: moquette
product: moquette
affected:
  - moquette < 0.18.1
patched:
  - moquette 0.18.1
published: '2026-09-23'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T13:34:44.800'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-95843'
references:
  - url: >-
      https://github.com/moquette-io/moquette/commit/affdc71fdba92dc020421678970ae70518fb6da2
    label: security-advisories@github.com
  - url: 'https://github.com/moquette-io/moquette/pull/962'
    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-5f42-97gr-vfhq
    label: security-advisories@github.com
  - url: >-
      https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00382
epssPercentile: 0.29453
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T17:57:47.160479Z'
scores:
  nvd: 7.5
  cna: 8.7
ingestedAt: '2026-09-23T17:28:14.850Z'
---

## Overview

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, PostOffice.subscribe parses a shared-subscription filter through SharedSubscriptionUtils.extractShareName before validating the complete $share/{shareName}/{topicFilter} structure. A remote client can send a filter such as $share/grp without a topic-filter portion, causing a StringIndexOutOfBoundsException while calculating the share name. The exception terminates command handling on the shared session event loop and can deny service to other client sessions assigned to that loop. This issue is fixed in version 0.18.1.

## Affected

- `moquette < 0.18.1`

## Remediation

Upgrade past the affected range:

- `moquette 0.18.1`