# CVE-2024-8403: Denial-of-Service Vulnerability in Ethernet port on MELSEC iQ-F Ethernet Module and EtherNet/IP Module

> Remote attackers can cause denial of service in Mitsubishi MELSEC iQ-F Ethernet modules by sending crafted SLMP packets.

- **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:** 19 Nov 2024
- **Updated:** 31 Mar 2026
- **Also known as:** GHSA-9v3g-gwx4-px97

## What is CVE-2024-8403?

CVE-2024-8403 is a high-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET, published on 19 Nov 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Validation of Specified Type of Input vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET versions 1.100 to 1.200 and FX5-ENET/IP versions 1.100 to 1.104 allows a remote attacker to cause a Denial of Service condition in Ethernet communication of the products by sending specially crafted SLMP packets.

Weakness: CWE-1287 (Improper Validation of Specified Type of Input)

## Which versions are affected by CVE-2024-8403?


## How do I fix CVE-2024-8403?

No fix has been published for CVE-2024-8403 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-8403 being exploited?

There is no known exploitation of CVE-2024-8403 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-8403 and fix it if it is affected.

What it is: CVE-2024-8403 is a high-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET, published on 19 Nov 2024. 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-2024-8403 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET. 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-2024-8403/ (Markdown: https://insights.sbomify.com/CVE-2024-8403/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-8403
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-8403
- OSV: https://osv.dev/vulnerability/CVE-2024-8403

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From sbomify Insights: https://insights.sbomify.com/CVE-2024-8403/
Summaries are generated and may contain mistakes; the official description above is the record.