# CVE-2025-65953: NanoMQ UAF of retain message due to invalid MQTTV5 properties

> A heap use-after-free in NanoMQ allows attackers to execute code or cause denial of service via malformed MQTTV5 retain messages.

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Nov 2025
- **Updated:** 26 Nov 2025
- **Also known as:** GHSA-r95p-wjm8-2qxr

## What is CVE-2025-65953?

CVE-2025-65953 is a medium-severity use after free vulnerability in nanomq, published on 25 Nov 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Prior to version 0.22.5, a Heap-Use-After-Free (UAF) vulnerability exists in the TCP transport component of NanoMQ, which relies on the underlying NanoNNG library (specifically in src/sp/transport/mqtt/broker_tcp.c). The vulnerability is due to improper resource management and premature cleanup of message and pipe structures under specific malformed MQTTV5 retain message traffic conditions. This issue has been patched in version 0.22.5.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-65953?


## How do I fix CVE-2025-65953?

No fix has been published for CVE-2025-65953 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-65953 being exploited?

There is no known exploitation of CVE-2025-65953 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-65953 and fix it if it is affected.

What it is: CVE-2025-65953 is a medium-severity use after free vulnerability in nanomq, published on 25 Nov 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-65953 in the wild and no public exploit code.

Affected product: nanomq. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-65953/ (Markdown: https://insights.sbomify.com/CVE-2025-65953/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-65953
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-65953
- OSV: https://osv.dev/vulnerability/CVE-2025-65953

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-65953/
Summaries are generated and may contain mistakes; the official description above is the record.