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. The function validates only that the fixed-header remaining_length is at least 4, then reads the 16-bit topic_name_size field from the broker-controlled packet and advances the parse pointer by that value without verifying that topic_name_size plus the surrounding overhead fits within remaining_length; it subsequently computes application_message_size as remaining_length - topic_name_size - 2 (QoS 0) or - 4 (QoS greater than 0) in unsigned arithmetic, producing an integer underflow that is then passed to memmove(). A PUBLISH packet with topic_name_size = 0xFFFF and remaining_length = 7 advances the parse pointer 65535 bytes past the receive buffer (out-of-bounds read) and causes an application_message_size near 2^32, crashing the process when the resulting memmove() is executed.
Configurations

No configuration.

History

14 Jun 2026, 18:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-06-14 18:17

Updated : 2026-06-16 15:36


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)