CVE-2026-54412

LiamBindle MQTT-C through version 1.1.6 contains a heap-based out-of-bounds read and integer underflow in the mqtt_unpack_publish_response function in src/mqtt.c that allows a remote unauthenticated attacker controlling an MQTT broker - or able to inject MQTT traffic into an unencrypted session - to crash a subscribed MQTT-C client and potentially disclose adjacent heap memory by sending a single crafted PUBLISH packet.

CVSS v3 8.2 HIGH

8.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://cwe.mitre.org/data/definitions/125.html
https://cwe.mitre.org/data/definitions/191.html
https://github.com/LiamBindle/MQTT-C
https://github.com/LiamBindle/MQTT-C/blob/v1.1.6/src/mqtt.c#L1334

Configurations

No configuration.

History

No history.

Information

Published : 2026-06-14 18:17

Updated : 2026-08-10 12:17

NVD link : CVE-2026-54412

Mitre link : CVE-2026-54412

CVE.ORG link : CVE-2026-54412

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

CWE-191

Integer Underflow (Wrap or Wraparound)

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La funci\u00f3n solo valida que el remaining_length del encabezado fijo sea al menos 4, luego lee el campo topic_name_size de 16 bits del paquete controlado por el broker y avanza el puntero de an\u00e1lisis por ese valor sin verificar que topic_name_size m\u00e1s la sobrecarga circundante encaje dentro de remaining_length; posteriormente calcula application_message_size como remaining_length - topic_name_size - 2 (QoS 0) o - 4 (QoS mayor que 0) en aritm\u00e9tica sin signo, produciendo un desbordamiento negativo de enteros que luego se pasa a memmove(). Un paquete PUBLISH con topic_name_size = 0xFFFF y remaining_length = 7 avanza el puntero de an\u00e1lisis 65535 bytes m\u00e1s all\u00e1 del b\u00fafer de recepci\u00f3n (lectura fuera de l\u00edmites) y provoca un application_message_size cercano a 2^32, provocando la ca\u00edda del proceso cuando se ejecuta el memmove() resultante."}], "lastModified": "2026-08-10T12:17:17.240", "sourceIdentifier": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"}