NULL pointer dereference in Nanomq
CVE-2026-32134
NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In versions 0.24.10 and below, when NanoMQ handles high-concurrency reconnect traffic using a reconnect-collision payload, the broker can crash due to a NULL pointer dereference during MQTT session resumption for clean_start=0 clients. The transport's p_peer callback (tcptran_pipe_peer()) iterates cpipe->subinfol while copying session metadata from the cached old pipe to the new reconnecting pipe, without checking whether the pointer is NULL. Under a reconnect race, cpipe->subinfol can be freed and set to NULL before session restore invokes this function, resulting in a remote unauthenticated Denial-of-Service (process crash) condition. This issue has been fixed in version 0.24.11.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Nanomq — versions < 0.24.11
- Nanomq Nanonng — versions < 0.24.11
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-32134?
- CVE-2026-32134 is a medium-severity vulnerability in Nanomq, classified under NULL Pointer Dereference. CVSS score: 5.9/10. Published 2026-05-19.
- How severe is CVE-2026-32134?
- Medium severity. CVSS v3 base score is 5.9 out of 10.