# CVE-2026-12806: Edimax BR-6478AC V2 buffer overflow in formWlSiteSurvey

Source: https://junglewise.ai/threats/cve-2026-12806-edimax-br-6478ac-v2-buffer-overflow-in-formwlsitesurvey  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-21. Updated: 2026-06-21  
License: CC BY 4.0 with a link back

CVE-2026-12806 · Severity: high · CVSS 8.8 · Published 2026-06-21

A security vulnerability exists in the Edimax BR-6478AC V2 wireless router. An attacker can exploit this flaw to crash the device or potentially take full control of it by sending a specially crafted web request. This could lead to a complete loss of internet connectivity or unauthorized access to the network traffic passing through the router.

Technologies: [Edimax BR-6478AC V2](https://junglewise.ai/threats/technologies/br-6478ac-v2). Vendors: [Edimax](https://junglewise.ai/threats/vendors/edimax).

## Quick answers

**Is CVE-2026-12806 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12806 being exploited in the wild.

**How severe is CVE-2026-12806?** High severity, with a CVSS score of 8.8, published 21 June 2026.

**Which products and versions are affected?** Edimax BR-6478AC V2 1.23.

**Is there a fix for CVE-2026-12806?** 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-2026-12806 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-12806?** Check whether you run Edimax BR-6478AC V2 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-6478AC V2 router running firmware version 1.23. The flaw is located within the formWlSiteSurvey function in the /goform/formWlSiteSurvey component, which handles POST requests. By manipulating the 'selSSID' argument, a remote attacker with low-level authentication can trigger the overflow. This can lead to arbitrary code execution or a system crash (denial of service). Although the vendor was notified, no patch has been released, and public exploit details are available.

## Affected products

- Edimax BR-6478AC V2 1.23

## Timeline

- 2026-06-21: disclosed: Public disclosure of the vulnerability and exploit details.
- 2026-06-21: advisory

## References

- [https://lavender-bicycle-a5a.notion.site/EDIMAX-BR6478ACV2-formWlSiteSurvey-34b53a41781f80669c10df409a0851d4?source=copy_link](https://lavender-bicycle-a5a.notion.site/EDIMAX-BR6478ACV2-formWlSiteSurvey-34b53a41781f80669c10df409a0851d4?source=copy_link)
- [https://vuldb.com/cve/CVE-2026-12806](https://vuldb.com/cve/CVE-2026-12806)
- [https://vuldb.com/submit/836668](https://vuldb.com/submit/836668)
- [https://vuldb.com/vuln/372600](https://vuldb.com/vuln/372600)
- [https://vuldb.com/vuln/372600/cti](https://vuldb.com/vuln/372600/cti)

## Related threats

- [Edimax BR-6478AC V2 command injection in POST Request Handler](https://junglewise.ai/threats/cve-2026-12810-edimax-br-6478ac-v2-command-injection-in-post-request-handler)
- [Edimax BR-6478AC V2 command injection in wiz_5in1_redirect](https://junglewise.ai/threats/cve-2026-12809-edimax-br-6478ac-v2-command-injection-in-wiz-5in1-redirect)
- [Edimax BR-6478AC V2 command injection in stainfo POST handler](https://junglewise.ai/threats/cve-2026-12808-edimax-br-6478ac-v2-command-injection-in-stainfo-post-handler)
- [Edimax BR-6478AC V2 command injection in setWAN](https://junglewise.ai/threats/cve-2026-12807-edimax-br-6478ac-v2-command-injection-in-setwan)