# CVE-2026-36810: Tenda W15E buffer overflow in formPortalAuth

Source: https://junglewise.ai/threats/cve-2026-36810-tenda-w15e-buffer-overflow-in-formportalauth  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-36810 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda W15E is a wireless router used for business and home networking. A security flaw in the device's portal authentication feature allows an attacker to crash the router by sending a specially crafted web request. This can lead to a complete loss of internet connectivity and network services for all connected users until the device is restarted.

Technologies: [Tenda W15E](https://junglewise.ai/threats/technologies/w15e). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-36810 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36810 being exploited in the wild.

**How severe is CVE-2026-36810?** Informational severity, with a CVSS score of 7.5, published 9 June 2026.

**Which products and versions are affected?** Tenda W15E v15.11.0.10.

**Is there a fix for CVE-2026-36810?** 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-2026-36810 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-36810?** Check whether you run Tenda W15E 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 exists in the Tenda W15E v15.11.0.10 firmware within the 'formPortalAuth' function. The vulnerability is caused by the unsafe use of 'strcpy' when processing the 'gotoUrl' HTTP parameter retrieved via 'websGetVar'. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request to the 'portalAuth' endpoint with an excessively long string in the 'gotoUrl' parameter. Successful exploitation results in a process crash or device instability, leading to a Denial of Service (DoS).

## Affected products

- Tenda W15E v15.11.0.10

## Timeline

- 2026-03-18: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure of vulnerability details
- 2026-06-09: advisory: NVD publication date

## References

- [https://github.com/xhh0124/SemVulLLM/tree/main/W15E/formPortalAuth](https://github.com/xhh0124/SemVulLLM/tree/main/W15E/formPortalAuth)

## Related threats

- [Tenda W15E buffer overflow in formAddWebAuthWhiteUser](https://junglewise.ai/threats/cve-2026-36817-tenda-w15e-buffer-overflow-in-formaddwebauthwhiteuser)
- [Tenda W15E buffer overflow in formAddWewifiWhiteUser](https://junglewise.ai/threats/cve-2026-36816-tenda-w15e-buffer-overflow-in-formaddwewifiwhiteuser)
- [Tenda W15E buffer overflow in formSetNetCheckTools](https://junglewise.ai/threats/cve-2026-36815-tenda-w15e-buffer-overflow-in-formsetnetchecktools)
- [Tenda W15E buffer overflow in formCropAndSetWewifiPic](https://junglewise.ai/threats/cve-2026-36813-tenda-w15e-buffer-overflow-in-formcropandsetwewifipic)
- [Tenda W15E buffer overflow in formDelwebAuthPic](https://junglewise.ai/threats/cve-2026-36811-tenda-w15e-buffer-overflow-in-formdelwebauthpic)