CVE-2026-61633
NanoMQ: Infinite Loop in UNSUBSCRIBE Decoder Leading to Remote DoS
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Low2.0 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L |
| NVDNVD · Deferred | 3.1 | Low2.0 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.34% · top 73% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.0.
Weakness
Affected products
References (4)
- https://github.com/nanomq/nanomq/security/advisories/GHSA-m7mp-rr3v-hmhr (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/nanomq/NanoNNG/pull/1518 (opens in a new tab)x_refsource_MISC
- https://github.com/nanomq/NanoNNG/commit/fa8d859bb39841e46cfc6cce280d242bd782ad3d (opens in a new tab)x_refsource_MISC
- https://github.com/nanomq/nanomq/releases/tag/0.24.14 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-61633)Record last updated .