CVE-2025-56353

7.5 HIGH
Published: January 20, 2026 Modified: February 03, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/JustDoIt0910/tinyMQTT/issues/19
Source: cve@mitre.org
Exploit Issue Tracking Third Party Advisory

1 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.1%
21th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

justdoit0910