# CVE-2026-86326: Security feature bypass in MGate MB3170 Series

> Attackers with high privileges can bypass firmware signature checks to install malicious images, enabling persistent code execution on Moxa industrial gateways.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-pccp-468g-6mp8

## What is CVE-2026-86326?

CVE-2026-86326 is a high-severity vulnerability in Moxa MGate MB3170 Series, published on 2 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

An improper verification of cryptographic signature vulnerability exists in protocol gateways because the device does not properly verify the cryptographic authenticity of firmware images before installation. An attacker with high privileges and access to the firmware update interface could provide a specially crafted or modified firmware image, causing it to be installed on the device. Successful exploitation could allow the attacker to execute unauthorized code, compromise the integrity and availability of the device, and persist malicious modifications across subsequent firmware updates.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-86326?


## How do I fix CVE-2026-86326?

No fix has been published for CVE-2026-86326 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86326 being exploited?

There is no known exploitation of CVE-2026-86326 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86326 and fix it if it is affected.

What it is: CVE-2026-86326 is a high-severity vulnerability in Moxa MGate MB3170 Series, published on 2 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86326 in the wild and no public exploit code.

Affected product: Moxa MGate MB3170 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-2026-86326/ (Markdown: https://insights.sbomify.com/CVE-2026-86326/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86326
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86326
- OSV: https://osv.dev/vulnerability/CVE-2026-86326

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86326/
Summaries are generated and may contain mistakes; the official description above is the record.