---
id: CVE-2026-101003
title: A weakness has been identified in Cesanta Mongoose up to 7.21
summary: >-
  A weakness has been identified in Cesanta Mongoose up to 7.21. Affected by
  this vulnerability is the function fn of the file
  tutorials/mqtt/mqtt-server/main.c of the component MQTT Broker. Executing a
  manipulation can lead to stack-based…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-119
  - CWE-121
vendor: Cesanta
product: Mongoose
affected:
  - Mongoose 7.0
  - Mongoose 7.1
  - Mongoose 7.2
  - Mongoose 7.3
  - Mongoose 7.4
  - Mongoose 7.5
  - Mongoose 7.6
  - Mongoose 7.7
  - Mongoose 7.8
  - Mongoose 7.9
  - Mongoose 7.10
  - Mongoose 7.11
  - Mongoose 7.12
  - Mongoose 7.13
  - Mongoose 7.14
  - Mongoose 7.15
  - Mongoose 7.16
  - Mongoose 7.17
  - Mongoose 7.18
  - Mongoose 7.19
  - Mongoose 7.20
  - Mongoose 7.21
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T06:16:31.310'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101003'
references:
  - url: 'https://github.com/cesanta/mongoose/'
    label: cna@vuldb.com
  - url: >-
      https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71
    label: cna@vuldb.com
  - url: 'https://github.com/cesanta/mongoose/releases/tag/7.22'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/cve/CVE-2026-101003'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/submit/920005'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410873'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410873/cti'
    label: cna@vuldb.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-28T06:04:04.033Z'
---

## Overview

A weakness has been identified in Cesanta Mongoose up to 7.21. Affected by this vulnerability is the function fn of the file tutorials/mqtt/mqtt-server/main.c of the component MQTT Broker. Executing a manipulation can lead to stack-based buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.22 addresses this issue. This patch is called a9df523f76f43a38bd53b4232b9cfd4c16869e71. Upgrading the affected component is advised.

## Remediation

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