CVE-2026-47276 NULL Pointer Dereference in REST API properties_parse via Malformed user_properties
An authenticated attacker can crash the NanoMQ broker by sending a malformed JSON array in user_properties to the publish API endpoint.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-47276?
CVE-2026-47276 is a medium-severity vulnerability in nanomq, published on 20 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In nanomq versions 0.24.11 and earlier, a NULL pointer dereference in `properties_parse()` allows an authenticated attacker to crash the NanoMQ broker by sending a POST request to `/api/v4/mqtt/publish` with `user_properties` as a JSON array instead of a JSON object. The crash occurs because `strlen()` is called on a NULL `item->string` pointer when iterating over array elements. An authenticated attacker can exploit this to crash the NanoMQ broker process. This is patched in version 0.24.14.
Weakness: CWE-476
Which versions are affected by CVE-2026-47276?
How do I fix CVE-2026-47276?
No fix has been published for CVE-2026-47276 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-47276 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47276 exists.
Sources
Also known as GHSA-qq2v-xvxg-3hvf.