CVE-2025-56353
- State
- Published
- Severity
- 7.5 High
- Published
- Jan 20, 2026
- Updated
- Jan 21, 2026
- Reserved
- Aug 16, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CISA-ADP |
Weaknesses
- CWE-401 Missing Release of Memory after Effective Lifetime
Affected Products
| Product | Versions |
|---|---|
n/an/a |
|
References
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.