CVE-2026-54412 MQTT-C Heap Out-of-Bounds Read and Integer Underflow in mqtt_unpack_publish_response()
A remote attacker can crash MQTT-C clients or disclose heap memory via a crafted PUBLISH packet due to integer underflow and out-of-bounds read.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-54412?
CVE-2026-54412 is a high-severity vulnerability in LiamBindle MQTT-C, published on 14 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-54412?
How do I fix CVE-2026-54412?
No fix has been published for CVE-2026-54412 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-54412 being exploited?
There is no known exploitation of CVE-2026-54412 in the wild and no public exploit code.
Sources
Also known as GHSA-28cw-rpqc-wqqj.