# CVE-2026-36806: Tenda W15E buffer overflow in formModifyWebAuthUser

Source: https://junglewise.ai/threats/cve-2026-36806-tenda-w15e-buffer-overflow-in-formmodifywebauthuser  
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-2026-36806 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda W15E enterprise router contains a security flaw in its web management interface. By sending a specially crafted web request to the device, an attacker can cause the router to crash or become unresponsive. This results in a denial of service, disrupting internet connectivity and local network operations for all connected users.

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

## Quick answers

**Is CVE-2026-36806 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36806 being exploited in the wild.

**How severe is CVE-2026-36806?** 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-2026-36806?** 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-2026-36806 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36806?** 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 'formModifyWebAuthUser' function. The vulnerability is triggered when the 'webAuthUserPwd' and 'webAuthUser' HTTP parameters, retrieved via 'websGetVar', are passed to an unsafe 'sprintf' call without proper bounds checking. An attacker can exploit this by sending a crafted HTTP POST request to the 'modifyWebAuthUser' action with excessively long strings in these parameters. This leads to memory corruption, resulting in a process crash or device instability (Denial of Service). No authentication requirements were specified in the disclosure, suggesting the endpoint may be reachable by unauthenticated network actors.

## Affected products

- Tenda W15E v15.11.0.10

## Timeline

- 2026-03-18: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure
- 2026-06-09: advisory: NVD published date

## References

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

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