{"id":"CVE-2026-47275","summary":"nanomq NULL Pointer Dereference in MQTTv5 Client CONNECT Decoder Leading to Remote DoS","details":"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-\u003enext` causes SIGSEGV at address `0x38` (NULL + `offsetof(property, next)`).\n\nThis 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.","aliases":["GHSA-52qr-3v49-wmx6"],"modified":"2026-07-22T05:29:49.844543123Z","published":"2026-07-20T16:43:03.704Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-476"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47275.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47275.json"},{"type":"ADVISORY","url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-52qr-3v49-wmx6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47275"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nanomq/nanomq","events":[{"introduced":"0"},{"last_affected":"69a97b3b39cc218f044f1c8896f4d3d8757bb394"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"last_affected":"0.24.11"}]}}],"versions":["0.24.11","0.24.10","0.24.9","0.24.8","0.24.7","0.24.6","0.24.5","0.24.4","0.24.3-5","0.24.3","0.24.2","0.24.1","0.24.0","0.23.10","0.23.9","0.23.8","0.23.7-11","0.23.7","0.23.6","0.23.5","0.23.4","0.23.3","0.23.2","0.23.1","0.23.0","0.22.10","0.22.8","0.22.7","0.22.6","0.22.2","0.22.3","0.22.1","0.22.0","0.21.10","0.21.9","0.21.8","0.21.7","0.21.6","0.21.5","0.21.2","0.21.1","0.21","0.20.8","0.20.6","0.20.5","0.20.0","0.19.5","0.19.1","0.19.0","0.18.2","0.18.1","0.17.8","0.17.5","0.17.2","0.16.5","0.16.3","0.16.2","0.16.0","0.15.5","0.15.3","0.15.2","0.15.1","0.15.0","0.14.8","0.14.5","0.12.1","0.14.1","0.14.0","0.13.8","0.13.6","0.13.0","0.12.5","0.12.2","0.12.0","0.11.82","0.11.8","0.11.5","0.11.3","0.11.2","0.11.0","0.10.8","0.10.5","0.10.1","0.9.7","0.9.5","0.9.2","0.9.0","0.8.6log","0.8.5","0.8.3","0.8.0","0.7.9","0.7.8","0.7.5","0.7.5rc","0.7.4rc","0.7.4","0.7.3","0.7.2","0.6.8","0.7.0","0.6.7rc","0.6.4","0.6.3","0.6.2","0.6.0","0.5.9","0.5.8","0.5.5","0.5.2","0.5.0","0.4.8","0.4.5","0.4.3","0.4.2","0.4.1","0.4.0","0.3.8","0.3.5","0.3.4","0.3.3","0.3.2","0.3.0","0.2.5","0.2.2","0.2.1","0.2.0","0.1.0","0.0.3","0.0.2","0.0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47275.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L"}]}