CVE-2026-44639 — NanoMQ: O(N²) Denial of Service in MQTT v5 Property Parsing
NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's MQTT v5 property decoder in nng/src/supplemental/mqtt/mqtt_codec.c uses property_append() to walk the entire linked list for…
Published: 2026-09-18 · CVSS: 3.7 · CVSS 3.1
NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's MQTT v5 property decoder in nng/src/supplemental/mqtt/mqtt_codec.c uses property_append() to walk the entire linked list for each property added by decode_buf_properties(). A remote unauthenticated client can supply a PUBLISH or SUBSCRIBE packet containing many User Properties, causing O(N²) linked-list insertion and CPU work that makes the broker unresponsive; repeated packets can sustain the denial of service. This issue is fixed in version 0.24.14.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7