CVE-2026-47275 (GCVE-0-2026-47275)
Vulnerability from cvelistv5 – Published: 2026-07-20 16:43 – Updated: 2026-07-20 18:56
VLAI
EPSS
VEX
Title
nanomq NULL Pointer Dereference in MQTTv5 Client CONNECT Decoder Leading to Remote DoS
Summary
In nanomq versions 0.24.11 and earlier, a NULL pointer dereference in `nni_mqttv5_msg_decode_connect()` allows a malicious MQTT broker to crash any connecting NanoMQ MQTTv5 client (including bridge mode) with a single packet, causing remote denial of service via SIGSEGV. In `nni_mqttv5_msg_decode_connect()` (`mqtt_codec.c:1863`), the code iterates over CONNECT properties using variable `prop` when it should use `will_prop`. When a CONNECT packet has no connect-level properties (`prop == NULL`) but has will properties (`will_prop != NULL`), dereferencing `prop->next` causes SIGSEGV at address `0x38` (NULL + `offsetof(property, next)`).
This affects both `nanomq_cli` and **NanoMQ bridge mode** (Core component), as both use the same `mqtt_client.c` receive path. This can lead to remote DoS if a malicious MQTT broker can crash the client process with a single 35-byte packet and persistent DoS if auto-reconnect causes infinite crash loop.
Severity
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-20 18:56 UTC
CWE
- CWE-476 - NULL Pointer Dereference
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/nanomq/nanomq/security/advisor… | x_refsource_CONFIRM |
Impacted products
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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