# CVE-2019-6535: Mitsubishi Electric MELSEC-Q Series PLCs Resource Exhaustion

> Remote attackers can crash the Ethernet stack and disrupt USB communication on Mitsubishi MELSEC-Q PLCs by sending specific bytes to Port 5007.

- **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:** 5 Feb 2019
- **Updated:** 26 Jun 2025
- **Also known as:** GHSA-6j5w-96r9-mm4v

## What is CVE-2019-6535?

CVE-2019-6535 is a high-severity denial of service vulnerability in Mitsubishi Electric Q03/04/06/13/26UDVCPU, published on 5 Feb 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mitsubishi Electric Q03/04/06/13/26UDVCPU: serial number 20081 and prior, Q04/06/13/26UDPVCPU: serial number 20081 and prior, and Q03UDECPU, Q04/06/10/13/20/26/50/100UDEHCPU: serial number 20101 and prior. A remote attacker can send specific bytes over Port 5007 that will result in an Ethernet stack crash and disruption to USB communication.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2019-6535?

It affects 18 products.


Products: Mitsubishielectric Q03udecpu Firmware, Mitsubishielectric Q03udvcpu Firmware, Mitsubishielectric Q04udehcpu Firmware, Mitsubishielectric Q04udpvcpu Firmware, Mitsubishielectric Q04udvcpu Firmware, Mitsubishielectric Q06udehcpu Firmware, Mitsubishielectric Q06udpvcpu Firmware, Mitsubishielectric Q06udvcpu Firmware, Mitsubishielectric Q100udehcpu Firmware, Mitsubishielectric Q10udehcpu Firmware, Mitsubishielectric Q13udehcpu Firmware, Mitsubishielectric Q13udpvcpu Firmware, Mitsubishielectric Q13udvcpu Firmware, Mitsubishielectric Q20udehcpu Firmware, Mitsubishielectric Q26udehcpu Firmware, Mitsubishielectric Q26udpvcpu Firmware, Mitsubishielectric Q26udvcpu Firmware, Mitsubishielectric Q50udehcpu Firmware.

## How do I fix CVE-2019-6535?

No fix has been published for CVE-2019-6535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-6535 being exploited?

There is no known exploitation of CVE-2019-6535 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6535 and fix it if it is affected.

What it is: CVE-2019-6535 is a high-severity denial of service vulnerability in Mitsubishi Electric Q03/04/06/13/26UDVCPU, published on 5 Feb 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-6535 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Q03/04/06/13/26UDVCPU. 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-2019-6535/ (Markdown: https://insights.sbomify.com/CVE-2019-6535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6535
- OSV: https://osv.dev/vulnerability/CVE-2019-6535

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-6535/
Summaries are generated and may contain mistakes; the official description above is the record.