# CVE-2026-36590: Denial of service in n/a

> A remote attacker can cause a denial of service in EMQ NanoMQ via the nni_qos_db_set function.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jul 2026
- **Updated:** 16 Jul 2026
- **Also known as:** GHSA-2gm5-wc63-c2pc

## What is CVE-2026-36590?

CVE-2026-36590 is a high-severity denial of service vulnerability in n/a, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue in EMQ NanoMQ v.0.24.9 allows a remote attacker to cause a denial of service via the nni_qos_db_set function in broker_tcp.c component

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-36590?

It affects 1 product.


Products: Emqx Nanomq.

## How do I fix CVE-2026-36590?

No fix has been published for CVE-2026-36590 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-36590 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-36590 exists.

Public exploit code:

- Public advisory and technical analysis for CVE-2026-36590, a NanoMQ v0.24.9 denial-of-service vulnerability. (github_poc): https://github.com/MoXie25/NanoMQ-Memory-Leak-Research

## Other vulnerabilities in n/a

- [CVE-2024-42655](https://insights.sbomify.com/CVE-2024-42655/): Missing authorization in n/a (high 8.8)
- [CVE-2025-59947](https://insights.sbomify.com/CVE-2025-59947/): NanoMQ has Buffer Overflow (high 8.5)
- [CVE-2023-34488](https://insights.sbomify.com/CVE-2023-34488/): Memory corruption in n/a (high 8.0)
- [CVE-2026-32135](https://insights.sbomify.com/CVE-2026-32135/): NanoMQ has Heap Buffer Overflow in URI Parameter Parsing (high 7.7)
- [CVE-2026-21888](https://insights.sbomify.com/CVE-2026-21888/): MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-36590 and fix it if it is affected.

What it is: CVE-2026-36590 is a high-severity denial of service vulnerability in n/a, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-36590 exists.

Affected product: n/a. 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-2026-36590/ (Markdown: https://insights.sbomify.com/CVE-2026-36590/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-36590
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-36590
- OSV: https://osv.dev/vulnerability/CVE-2026-36590

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-36590/
Summaries are generated and may contain mistakes; the official description above is the record.