CVE-2026-101003
Received Received - Intake

Stack-Based Buffer Overflow in Cesanta Mongoose

Publication date: 2026-09-28

Last updated on: 2026-09-28

Assigner: VulDB

Description
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.

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Meta Information

Published
2026-09-28
Last Modified
2026-09-28
Generated
2026-09-28
AI Q&A
2026-09-28
EPSS Evaluated
N/A
NVD
CVE-2026-101003
EUVD
EUVD-2026-88089

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
cesanta mongoose to 7.22 (exc)
cesanta mongoose 7.22

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-121 A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CWE-119 The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

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Executive Summary

This vulnerability is a stack-based buffer overflow in the Cesanta Mongoose MQTT Broker component. It exists in the function fn of the file tutorials/mqtt/mqtt-server/main.c in versions up to 7.21. A remote attacker can exploit this by sending manipulated input, causing a buffer overflow. The issue is fixed in version 7.22 with patch a9df523f76f43a38bd53b4232b9cfd4c16869e71.

Detection Guidance

To detect this vulnerability, check the version of Mongoose installed on your system. If it is version 7.21 or earlier, the system is vulnerable. Use commands like 'grep' or 'find' to locate mongoose.c or mongoose.h files and inspect their version or modification date. For example: grep -r 'Mongoose' /path/to/project or find /path/to/project -name 'mongoose.c'.

Impact Analysis

The vulnerability allows remote attackers to execute arbitrary code or cause a denial of service by triggering a stack overflow. This could lead to system crashes, unauthorized access, or data corruption if exploited. Systems using affected Mongoose versions for MQTT Broker functionality are at risk.

Compliance Impact

The vulnerability involves a stack-based buffer overflow in the MQTT Broker component of Cesanta Mongoose up to version 7.21. This type of vulnerability could potentially lead to remote code execution or denial of service, which may compromise data integrity and availability. For compliance with GDPR, this could affect the security of personal data processing, while for HIPAA, it might impact the confidentiality and integrity of protected health information. However, the provided context does not explicitly detail compliance impacts.

Mitigation Strategies

Immediately upgrade Mongoose to version 7.22 or later. Download the latest release from the official repository or apply the patch a9df523f76f43a38bd53b4232b9cfd4c16869e71. Replace the vulnerable files in your project with the updated version and recompile your application.

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