NULL pointer dereference in Emqx Nanomq
CVE-2026-32696
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.
EPSS: 0.004 (32.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L.
Affected products
- Emqx Nanomq
- Nanomq — versions >= 0.24.6, < 0.24.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-32696?
- CVE-2026-32696 is a low-severity vulnerability in Emqx Nanomq, classified under NULL Pointer Dereference. CVSS score: 3.1/10. Published 2026-03-30.
- How severe is CVE-2026-32696?
- Low severity. CVSS v3 base score is 3.1 out of 10.