🛡️ CVE-2025-56353
🟠 CVSS 7.5 — High ⚠️ Exploit Public CWE-401 NVD
7.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), a memory leak occurs due to the broker's failure to validate or reject malformed UTF-8 strings in topic filters. An attacker can exploit this by sending repeated subscription requests with arbitrarily large or invalid filter payloads. Each request causes memory to be allocated for the malformed topic filter, but the broker does not free the associated memory, leading to unbounded heap growth and potential denial of service under sustained attack.

Details

Severity HIGH
CVSS Score 7.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE CWE-401
Public Exploit ⚠️ Yes
Source NVD
Published 2026-01-20
Updated 2026-06-02
Modified 2026-02-03
Fix URL N/A

Affected Packages

Software From version Fixed in
tinymqtt — —

References

Exploit, Issue Tracking, Third Party Advisory https://github.com/JustDoIt0910/tinyMQTT/issues/19

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