# CVE-2026-9399: Edimax BR-6675nD buffer overflow in formsetPPPoE

Source: https://junglewise.ai/threats/cve-2026-9399-edimax-br-6675nd-buffer-overflow-in-formsetpppoe  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-24. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9399 · Severity: high · CVSS 8.8 · Published 2026-05-24

A security vulnerability exists in the Edimax BR-6675nD wireless router. An attacker can exploit this flaw to cause a system crash or potentially take full control of the device by sending a specially crafted network request. This could lead to a complete loss of internet connectivity or unauthorized access to the local network.

Technologies: [Edimax BR-6675nD](https://junglewise.ai/threats/technologies/br-6675nd). Vendors: [Edimax](https://junglewise.ai/threats/vendors/edimax).

## Quick answers

**Is CVE-2026-9399 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9399 being exploited in the wild.

**How severe is CVE-2026-9399?** High severity, with a CVSS score of 8.8, published 24 May 2026.

**Which products and versions are affected?** Edimax BR-6675nD 1.12.

**Is there a fix for CVE-2026-9399?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-9399 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-9399?** Check whether you run Edimax BR-6675nD at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stack-based buffer overflow vulnerability exists in the Edimax BR-6675nD router version 1.12. The flaw is located within the 'formsetPPPoE' function in the '/goform/formsetPPPoE' file, which serves as a POST request handler. By manipulating the 'pppUserName' argument, a remote attacker with low privileges can trigger the overflow. This occurs due to improper restriction of operations within the bounds of a memory buffer (CWE-119/CWE-120). Successful exploitation can lead to remote code execution or a complete system crash. As of the advisory date, the vendor has not responded to disclosure attempts, and no patch is currently available.

## Affected products

- Edimax BR-6675nD 1.12

## Timeline

- 2026-05-24: advisory: Initial disclosure of the vulnerability
- 2026-05-24: disclosed: Exploit code made public

## References

- [https://lavender-bicycle-a5a.notion.site/EDIMAX-BR-6675nD-formsetPPPoE-34b53a41781f8025abcded9e7d0734ef?source=copy_link](https://lavender-bicycle-a5a.notion.site/EDIMAX-BR-6675nD-formsetPPPoE-34b53a41781f8025abcded9e7d0734ef?source=copy_link)
- [https://vuldb.com/submit/811561](https://vuldb.com/submit/811561)
- [https://vuldb.com/vuln/365380](https://vuldb.com/vuln/365380)
- [https://vuldb.com/vuln/365380/cti](https://vuldb.com/vuln/365380/cti)

## Related threats

- [Edimax BR-6675nD command injection in /goform/stainfo](https://junglewise.ai/threats/cve-2026-9439-edimax-br-6675nd-command-injection-in-goform-stainfo)
- [Edimax BR-6675nD command injection in POST Request Handler](https://junglewise.ai/threats/cve-2026-9423-edimax-br-6675nd-command-injection-in-post-request-handler)
- [Edimax BR-6675nD buffer overflow in formWlSiteSurvey](https://junglewise.ai/threats/cve-2026-9403-edimax-br-6675nd-buffer-overflow-in-formwlsitesurvey)
- [Edimax BR-6675nD command injection in formWlanMP](https://junglewise.ai/threats/cve-2026-9402-edimax-br-6675nd-command-injection-in-formwlanmp)
- [Edimax BR-6675nD buffer overflow in formWanTcpipSetup](https://junglewise.ai/threats/cve-2026-9401-edimax-br-6675nd-buffer-overflow-in-formwantcpipsetup)