{"id":"CVE-2026-61633","state":"PUBLISHED","title":"NanoMQ: Infinite Loop in UNSUBSCRIBE Decoder Leading to Remote DoS","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.","publishedAt":"2026-09-18T16:18:57.029Z","updatedAt":"2026-09-18T17:26:49.956Z","severity":{"score":2,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["nanomq nanomq"],"affected":[{"vendor":"nanomq","product":"nanomq","versions":[{"version":"< 0.24.14","status":"affected"}]}],"references":["https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","https://github.com/nanomq/NanoNNG/pull/1518","https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d","https://github.com/nanomq/nanomq/releases/tag/0.24.14"],"weaknesses":["CWE-835"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/61xxx/CVE-2026-61633.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-61633","state":"PUBLISHED","datePublished":"2026-09-18T16:18:57.029Z","dateUpdated":"2026-09-18T17:26:49.956Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-10T17:38:57.111Z"},"containers":{"cna":{"title":"NanoMQ: Infinite Loop in UNSUBSCRIBE Decoder Leading to Remote DoS","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."}],"affected":[{"vendor":"nanomq","product":"nanomq","versions":[{"version":"< 0.24.14","status":"affected"}]}],"references":[{"url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","name":"https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/nanomq/NanoNNG/pull/1518","name":"https://github.com/nanomq/NanoNNG/pull/1518","tags":["x_refsource_MISC"]},{"url":"https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d","name":"https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d","tags":["x_refsource_MISC"]},{"url":"https://github.com/nanomq/nanomq/releases/tag/0.24.14","name":"https://github.com/nanomq/nanomq/releases/tag/0.24.14","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":2,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-835","lang":"en","description":"CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-18T16:18:57.029Z"},"source":{"advisory":"GHSA-m7mp-rr3v-hmhr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T17:26:25.126842Z","id":"CVE-2026-61633","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-18T17:26:49.956Z"}}]}}}