# CVE-2026-9459: Edimax EW-7438RPn stack overflow in formConnectionSetting

Source: https://junglewise.ai/threats/cve-2026-9459-edimax-ew-7438rpn-stack-overflow-in-formconnectionsetting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-25. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9459 · Severity: high · CVSS 8.8 · Published 2026-05-25

A security vulnerability exists in the Edimax EW-7438RPn Wi-Fi extender, a device used to boost wireless network coverage. An attacker can exploit this flaw to crash the device or potentially take full control of it by sending specially crafted network requests. This could lead to a complete loss of internet connectivity through the extender or unauthorized access to the device's settings and traffic.

Technologies: [Edimax EW-7438RPn](https://junglewise.ai/threats/technologies/ew-7438rpn). Vendors: [Edimax](https://junglewise.ai/threats/vendors/edimax).

## Quick answers

**Is CVE-2026-9459 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9459 being exploited in the wild.

**How severe is CVE-2026-9459?** High severity, with a CVSS score of 8.8, published 25 May 2026.

**Which products and versions are affected?** Edimax EW-7438RPn 1.31.

**Is there a fix for CVE-2026-9459?** 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-2026-9459 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-9459?** Check whether you run Edimax EW-7438RPn 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 'webs' binary of the Edimax EW-7438RPn firmware version 1.31. The vulnerability is located within the 'formConnectionSetting' function in the '/goform/formConnectionSetting' file. The root cause is a failure to validate the length of the 'max_Conn' and 'timeOut' HTTP POST parameters before copying them into local stack variables. A remote attacker with low privileges (authenticated) can exploit this by sending an oversized string in these parameters, overwriting the function's return address to achieve arbitrary code execution or a device crash (DoS). A public exploit has been released, and the vendor has reportedly not responded to disclosure attempts.

## Affected products

- Edimax EW-7438RPn 1.31

## Timeline

- 2026-05-25: disclosed: Initial public disclosure via VulDB and GitHub
- 2026-05-25: advisory: CVE-2026-9459 published

## References

- [https://github.com/wudipjq/my_vuln/blob/main/Edimax/vuln_12/12.md](https://github.com/wudipjq/my_vuln/blob/main/Edimax/vuln_12/12.md)
- [https://vuldb.com/submit/813896](https://vuldb.com/submit/813896)
- [https://vuldb.com/vuln/365440](https://vuldb.com/vuln/365440)
- [https://vuldb.com/vuln/365440/cti](https://vuldb.com/vuln/365440/cti)

## Related threats

- [Edimax EW-7438RPn stack overflow in formSDHCP](https://junglewise.ai/threats/cve-2026-9482-edimax-ew-7438rpn-stack-overflow-in-formsdhcp)
- [Edimax EW-7438RPn stack overflow in formStats](https://junglewise.ai/threats/cve-2026-9481-edimax-ew-7438rpn-stack-overflow-in-formstats)
- [Edimax EW-7438RPn stack overflow in formrefresh](https://junglewise.ai/threats/cve-2026-9480-edimax-ew-7438rpn-stack-overflow-in-formrefresh)
- [Edimax EW-7438RPn stack overflow in formLogout](https://junglewise.ai/threats/cve-2026-9479-edimax-ew-7438rpn-stack-overflow-in-formlogout)
- [Edimax EW-7438RPn stack overflow in formLicence](https://junglewise.ai/threats/cve-2026-9463-edimax-ew-7438rpn-stack-overflow-in-formlicence)