CVE-2026-32696 Null dereference in nanomq
Remote attackers can crash the NanoMQ broker by sending an MQTT CONNECT packet without credentials when HTTP authentication is enabled with specific placeholders.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-32696?
CVE-2026-32696 is a low-severity vulnerability in nanomq, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In NanoMQ version 0.24.6, after enabling auth.http_auth (HTTP authentication), when a client connects to the broker using MQTT CONNECT without providing username/password, and the configuration params uses the placeholders %u / %P (e.g., username="%u", password="%P"), the HTTP request construction phase enters auth_http.c:set_data(). This results in calling strlen() on a NULL pointer, causing a SIGSEGV crash. This crash can be triggered remotely, resulting in a denial of service. This issue has been patched in version 0.24.7.
Weakness: CWE-476
Which versions are affected by CVE-2026-32696?
It affects 1 product.
Products include Emqx Nanomq.
How do I fix CVE-2026-32696?
No fix has been published for CVE-2026-32696 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-32696 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32696 exists.
Other vulnerabilities in nanomq
Sources
Also known as GHSA-77f4-wvq8-mp3p.