Quick answers
- Is CVE-2026-47275 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-47275 being exploited in the wild.
- How severe is CVE-2026-47275?
- Low severity, with a CVSS score of 2.6, published 20 July 2026.
- Which products and versions are affected?
- EMQ NanoMQ <= 0.24.11.
- Is there a fix for CVE-2026-47275?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-47275 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-47275?
- Check whether you run EMQ NanoMQ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A NULL pointer dereference exists in the `nni_mqttv5_msg_decode_connect()` function within `mqtt_codec.c`. The vulnerability is triggered when the decoder incorrectly uses the `prop` variable instead of `will_prop` while iterating over MQTTv5 CONNECT properties. If a packet contains 'will' properties but no connect-level properties, the code attempts to dereference a NULL pointer, leading to a SIGSEGV crash. This affects both the `nanomq_cli` and the core bridge mode. An attacker controlling a malicious broker can trigger this with a single 35-byte packet, potentially causing a persistent DoS via infinite crash loops during auto-reconnection.
Affected products
- nanomq nanomq <= 0.24.11
Timeline
- 2026-06-26: disclosed: Advisory published on GitHub
- 2026-07-20: advisory: CVE published to NVD