# CVE-2026-39453: Red Lion Controls N-Tron 700 Series Reachable Assertion

> An attacker can cause a Red Lion Controls N-Tron switch to reboot by accessing a specific URL, resulting in a denial of service.

- **Severity:** High 8.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:H/SA:H`)
- **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:** 9 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-jp3p-vmv4-q5ff

## What is CVE-2026-39453?

CVE-2026-39453 is a high-severity denial of service vulnerability in Red Lion Controls 700 Series, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Navigating to a certain URL on the switch’s web server causes the switch to reboot. This can be automated using a tool like curl to create DoS conditions where the switch constantly reboots.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-39453?


## How do I fix CVE-2026-39453?

No fix has been published for CVE-2026-39453 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39453 being exploited?

There is no known exploitation of CVE-2026-39453 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39453 and fix it if it is affected.

What it is: CVE-2026-39453 is a high-severity denial of service vulnerability in Red Lion Controls 700 Series, published on 9 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-39453 in the wild and no public exploit code.

Affected product: Red Lion Controls 700 Series. 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-2026-39453/ (Markdown: https://insights.sbomify.com/CVE-2026-39453/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39453
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39453
- OSV: https://osv.dev/vulnerability/CVE-2026-39453

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39453/
Summaries are generated and may contain mistakes; the official description above is the record.