# CVE-2026-36817: Tenda W15E buffer overflow in formAddWebAuthWhiteUser

Source: https://junglewise.ai/threats/cve-2026-36817-tenda-w15e-buffer-overflow-in-formaddwebauthwhiteuser  
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-2026-36817 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda W15E is a wireless router designed for small business and enterprise networking. A security flaw in the router's web management interface allows an attacker to crash the device by sending a specially crafted network request. This can lead to a total loss of internet connectivity and network services for all connected users, requiring a manual restart to recover.

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

## Quick answers

**Is CVE-2026-36817 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36817 being exploited in the wild.

**How severe is CVE-2026-36817?** 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-2026-36817?** 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-2026-36817 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36817?** 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 router within the 'formAddWebAuthWhiteUser' function. The vulnerability is triggered when the 'webAuthWhiteUserInfo' HTTP parameter is processed. The application uses 'websGetVar' to retrieve the user-supplied string and subsequently performs a 'strncpy' operation into a fixed-size buffer ('temp') without adequate bounds checking. Specifically, the length calculation using 'strchr' to find a newline character can result in a value exceeding the destination buffer's capacity. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request containing a long string followed by a newline character, resulting in a process crash or device instability (Denial of Service).

## 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 published the CVE record

## References

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

## Related threats

- [Tenda W15E buffer overflow in formAddWewifiWhiteUser](https://junglewise.ai/threats/cve-2026-36816-tenda-w15e-buffer-overflow-in-formaddwewifiwhiteuser)
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- [Tenda W15E buffer overflow in formPortalAuth](https://junglewise.ai/threats/cve-2026-36810-tenda-w15e-buffer-overflow-in-formportalauth)