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.
History

Wed, 21 Jan 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-401
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 21 Jan 2026 11:30:00 +0000

Type Values Removed Values Added
First Time appeared Justdoit0910
Justdoit0910 tinymqtt
Vendors & Products Justdoit0910
Justdoit0910 tinymqtt

Tue, 20 Jan 2026 16:00:00 +0000

Type Values Removed Values Added
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.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-01-20T00:00:00.000Z

Updated: 2026-01-21T14:39:58.418Z

Reserved: 2025-08-16T00:00:00.000Z

Link: CVE-2025-56353

cve-icon Vulnrichment

Updated: 2026-01-21T14:39:54.107Z

cve-icon NVD

Status : Received

Published: 2026-01-20T16:16:05.700

Modified: 2026-01-21T15:16:06.640

Link: CVE-2025-56353

cve-icon Redhat

No data.