# CVE-2026-9426: Edimax EW-7438RPn stack overflow in formHwSet

Source: https://junglewise.ai/threats/cve-2026-9426-edimax-ew-7438rpn-stack-overflow-in-formhwset  
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-2026-9426 · 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 increase the range of wireless networks. An attacker can exploit this flaw to crash the device or potentially take full control of it by sending specially crafted web requests. This could lead to a complete loss of internet connectivity through the extender and unauthorized access to the device's settings.

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

## Quick answers

**Is CVE-2026-9426 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9426 being exploited in the wild.

**How severe is CVE-2026-9426?** 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-2026-9426?** 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-2026-9426 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-9426?** 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 Wi-Fi extender (firmware version 1.31). The flaw is located within the 'formHwSet' function in the '/goform/formHwSet' handler. The function fails to validate the length of several input parameters, including 'Anntena', 'Mcs', 'regDomain', and others, before copying them into a fixed-size stack buffer. A remote attacker with low privileges (authenticated) can exploit this by sending a POST request with excessively long strings, overwriting the return address to achieve arbitrary code execution or a device crash (DoS). As of the advisory date, the vendor has not responded to disclosure attempts, and no patch is available.

## Affected products

- Edimax EW-7438RPn 1.31

## Timeline

- 2026-05-25: disclosed: Public disclosure of the vulnerability and PoC.
- 2026-05-25: advisory: CVE-2026-9426 published.

## References

- [https://github.com/wudipjq/my_vuln/blob/main/Edimax/vuln_10/10.md](https://github.com/wudipjq/my_vuln/blob/main/Edimax/vuln_10/10.md)
- [https://vuldb.com/submit/813894](https://vuldb.com/submit/813894)
- [https://vuldb.com/vuln/365407](https://vuldb.com/vuln/365407)
- [https://vuldb.com/vuln/365407/cti](https://vuldb.com/vuln/365407/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)