# CVE-2026-5612: Belkin F9K1015 stack buffer overflow in formWlEncrypt

Source: https://junglewise.ai/threats/cve-2026-5612-belkin-f9k1015-stack-buffer-overflow-in-formwlencrypt  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-06. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-5612 · Severity: high · CVSS 8.8 · Published 2026-04-06

A security vulnerability exists in the Belkin F9K1015 wireless router. This flaw allows a remote attacker to crash the device or potentially take full control of it by sending a specially crafted web request. Such an exploit could lead to a complete loss of internet connectivity for the network or unauthorized access to the router's settings and traffic.

Technologies: [Belkin F9k1015](https://junglewise.ai/threats/technologies/f9k1015), [Belkin F9k1015 Firmware](https://junglewise.ai/threats/technologies/f9k1015-firmware). Vendors: [Belkin](https://junglewise.ai/threats/vendors/belkin).

## Quick answers

**Is CVE-2026-5612 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5612 being exploited in the wild.

**How severe is CVE-2026-5612?** High severity, with a CVSS score of 8.8, published 6 April 2026.

**Which products and versions are affected?** Belkin F9k1015 1.00.10.

**Is there a fix for CVE-2026-5612?** 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-2026-5612 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-5612?** Check whether you run Belkin F9k1015 or Belkin F9k1015 Firmware 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 Belkin F9K1015 firmware version 1.00.10. The flaw is located within the 'formWlEncrypt' function in the '/goform/formWlEncrypt' file. The vulnerability is caused by the unsafe use of the 'strcpy' function when processing the user-provided 'webpage' parameter, which is copied into a fixed-size stack buffer ('reboot_msg') without adequate length validation. A remote attacker with low privileges can exploit this by sending a POST request with an oversized 'webpage' argument, leading to a denial of service (DoS) or remote code execution (RCE). As of the advisory date, the vendor has not responded to disclosure attempts, and no patch is currently available.

## Affected products

- Belkin F9K1015 1.00.10

## Timeline

- 2026-04-05: disclosed: Vulnerability disclosed via VulDB and GitHub PoC.
- 2026-04-06: advisory: NVD publication date.

## References

- [https://github.com/Litengzheng/vuldb_new/blob/main/Belkin%20F9K1015/vul_7/README.md](https://github.com/Litengzheng/vuldb_new/blob/main/Belkin%20F9K1015/vul_7/README.md)
- [https://vuldb.com/submit/785551](https://vuldb.com/submit/785551)
- [https://vuldb.com/vuln/355403](https://vuldb.com/vuln/355403)
- [https://vuldb.com/vuln/355403/cti](https://vuldb.com/vuln/355403/cti)

## Related threats

- [Belkin F9K1015 stack-based buffer overflow in formSetFirewall](https://junglewise.ai/threats/cve-2026-5629-belkin-f9k1015-stack-based-buffer-overflow-in-formsetfirewall)
- [Belkin F9K1015 stack overflow in formSetSystemSettings](https://junglewise.ai/threats/cve-2026-5628-belkin-f9k1015-stack-overflow-in-formsetsystemsettings)
- [Belkin F9K1015 stack buffer overflow in formSetPassword](https://junglewise.ai/threats/cve-2026-5614-belkin-f9k1015-stack-buffer-overflow-in-formsetpassword)
- [Belkin F9K1015 stack-based buffer overflow in formReboot](https://junglewise.ai/threats/cve-2026-5613-belkin-f9k1015-stack-based-buffer-overflow-in-formreboot)
- [Belkin F9K1015 stack-based buffer overflow in formCrossBandSwitch](https://junglewise.ai/threats/cve-2026-5611-belkin-f9k1015-stack-based-buffer-overflow-in-formcrossbandswitch)