{"id":"CVE-2026-61633","title":"NanoMQ is an MQTT broker","summary":"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 pa…","severity":"low","cvss":2,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L","cwe":["CWE-835"],"vendor":"nanomq","product":"nanomq","affected":["nanomq < 0.24.14"],"published":"2026-09-18","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:09.433","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-61633","references":[{"url":"https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d","label":"security-advisories@github.com"},{"url":"https://github.com/nanomq/NanoNNG/pull/1518","label":"security-advisories@github.com"},{"url":"https://github.com/nanomq/nanomq/releases/tag/0.24.14","label":"security-advisories@github.com"},{"url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","label":"security-advisories@github.com"},{"url":"https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-18T17:26:25.126842Z"},"ingestedAt":"2026-09-18T16:45:41.410Z","epss":0.00253,"epssPercentile":0.17124,"slug":"CVE-2026-61633","body":"## Overview\n\nNanoMQ 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":23,"depthScoreParts":{"impact":11,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":207053,"id":"CVE-2026-61633","ts":1789753639242,"field":"exploit_available","old":"false","new":"true"}]}