# CVE-2026-8806: Denial-of-service (DoS) vulnerability in MELSEC iQ-F Series FX5-ENET/IP Ethernet module

> Remote attackers can cause denial of service in Mitsubishi MELSEC iQ-F Ethernet modules by flooding the port with packets, stopping communication functions.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Jun 2026
- **Updated:** 22 Jun 2026
- **Also known as:** GHSA-8vpf-2whm-fffj

## What is CVE-2026-8806?

CVE-2026-8806 is a high-severity denial of service vulnerability in Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP, published on 19 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Expected Behavior Violation vulnerability in Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP all versions allows a remote attacker to cause a denial-of-service (DoS) condition in the affected product by continuously sending a large number of communication packets to the Ethernet port of the product in a short period of time, increasing the processing load of the product, preventing the internal anomaly-detection processing from being performed, and causing the communication function to stop.

Weakness: CWE-440 (Expected Behavior Violation)

## Which versions are affected by CVE-2026-8806?


## How do I fix CVE-2026-8806?

No fix has been published for CVE-2026-8806 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8806 being exploited?

There is no known exploitation of CVE-2026-8806 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8806 and fix it if it is affected.

What it is: CVE-2026-8806 is a high-severity denial of service vulnerability in Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP, published on 19 Jun 2026. 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-2026-8806 in the wild and no public exploit code.

Affected product: Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP. 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-2026-8806/ (Markdown: https://insights.sbomify.com/CVE-2026-8806/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8806
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8806
- OSV: https://osv.dev/vulnerability/CVE-2026-8806

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-8806/
Summaries are generated and may contain mistakes; the official description above is the record.