CVE-2025-56353

HIGH EPSS 20.4%
Published Jan 20, 20265mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Jan 20, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
20.4% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-401

Affected Products 1

VendorProductVersionRange
justdoit0910tinymqtt2024-02-18any

References 1

  • github.com https://github.com/JustDoIt0910/tinyMQTT/issues/19
    ExploitIssue TrackingThird Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.