Description
NanoMQ is an MQTT broker. Prior to 0.24.14, the NanoMQ client function nni_mqtt_msg_decode_unsubscribe() in nng/src/supplemental/mqtt/mqtt_codec.c does not handle a failed read_uint16() while counting topics in a malformed UNSUBSCRIBE packet. A zero-length topic followed by trailing data can leave buf.curpos unchanged while topic_count continues to increase, allowing a malicious MQTT broker to hang a connecting MQTT 3.1.1 client, consume CPU and memory, and repeatedly deny service when automatic reconnection is enabled. The broker-side nmq_unsubinfo_decode path is not affected. This issue is fixed in version 0.24.14.
References5
Metrics
- CVSS 3.1
-
2.0
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L - EPSS — exploit probability
- 0% percentile: 27 · as of 8 November 2026
- CWE
- CWE-835
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