CVE-2026-61633
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.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L
- Puntuación base: 2
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.34%
- Percentil entre todas las CVEs puntuadas: 25
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution75 % - Impacto principal
T1499.004Application or System Exploitationimpact80 % - Impacto secundario
T1499.003Application Exhaustion Floodimpact70 %
CVE-2026-61633 requiere interacción del usuario (UI:R) para que un cliente MQTT se conecte a un broker malicioso que envía paquetes UNSUBSCRIBE malformados. El impacto es DoS mediante consumo de CPU/memoria y hang del cliente, clasificado como T1499.004 (DoS de aplicación) y T1499.003 (DoS de recurs
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-835
Referencias
- https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d
- https://github.com/nanomq/NanoNNG/pull/1518
- https://github.com/nanomq/nanomq/releases/tag/0.24.14
- https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr
- https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-61633",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-61633",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-18T17:26:25.126842Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 2,
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "LOW",
"privilegesRequired": "HIGH",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 0.5
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "nanomq",
"product": "nanomq",
"versions": [
{
"status": "affected",
"version": "< 0.24.14"
}
]
}
]
}
],
"published": "2026-09-18T17:16:58.340",
"references": [
{
"url": "https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/nanomq/NanoNNG/pull/1518",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/nanomq/nanomq/releases/tag/0.24.14",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-835"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"lastModified": "2026-09-18T18:17:09.433",
"sourceIdentifier": "security-advisories@github.com"
}