{"id":"CVE-2026-47275","aliases":["EUVD-2026-46023","GHSA-52qr-3v49-wmx6"],"status":"published","title":"nanomq NULL Pointer Dereference in MQTTv5 Client CONNECT Decoder Leading to Remote DoS","description":"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.","severity":{"version":"3.1","score":2.6,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00273,"percentile":0.19941,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-476"],"published":"2026-07-20T16:43:03Z","modified":"2026-10-28T02:30:55Z","products":[{"vendor":"nanomq","product":"nanomq"}],"references":[{"url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-52qr-3v49-wmx6","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47275.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47275","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-47275","title":"nanomq NULL Pointer Dereference in MQTTv5 Client CONNECT Decoder Leading to Remote DoS","description":"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.","status":"published","published":"2026-07-20T16:43:03.704Z","modified":"2026-07-20T18:56:28.995Z","cvss":[{"version":"3.1","score":2.6,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T13:36:40.478484Z"}],"euvd":[{"id":"EUVD-2026-46023","description":"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.","status":"published","published":"2026-07-20T16:43:03Z","modified":"2026-07-20T18:56:28Z","cvss":[{"version":"3.1","score":2.6,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T18:19:48.530346Z"}],"nvd":[{"id":"CVE-2026-47275","description":"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.","status":"published","published":"2026-07-20T17:17:10.12Z","modified":"2026-07-23T16:04:11.74Z","cvss":[{"version":"3.1","score":2.6,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:12:31.024898Z"}],"osv":[{"id":"CVE-2026-47275","title":"nanomq NULL Pointer Dereference in MQTTv5 Client CONNECT Decoder Leading to Remote DoS","description":"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.","status":"published","published":"2026-07-20T16:43:03.704Z","modified":"2026-10-28T02:30:55.095772746Z","cvss":[{"version":"3.1","score":2.6,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T15:45:06.231145Z"}]}}