# CVE-2026-36794: Tenda W3 Wireless Router stack overflow in R7WebsSecurityHandler

Source: https://junglewise.ai/threats/cve-2026-36794-tenda-w3-wireless-router-stack-overflow-in-r7webssecurityhandler  
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-2026-36794 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda W3 wireless router, used for home and small office networking, contains a security flaw in its web management interface. An attacker can send a specially crafted web request to the device to cause it to crash or reboot. This results in a denial of service, disrupting internet connectivity for all connected users.

Technologies: [Tenda W3 Wireless Router](https://junglewise.ai/threats/technologies/w3-wireless-router). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-36794 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36794 being exploited in the wild.

**How severe is CVE-2026-36794?** Informational severity, with a CVSS score of 7.5, published 9 June 2026.

**Which products and versions are affected?** Tenda W3 Wireless Router v1.0.0.3(2204).

**Is there a fix for CVE-2026-36794?** 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-2026-36794 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36794?** Check whether you run Tenda W3 Wireless Router 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 R7WebsSecurityHandler function of the Tenda W3 router (firmware v1.0.0.3(2204)). The vulnerability is triggered when the 'username' and 'password' parameters are retrieved via websGetVar without length validation. Specifically, the 'username' parameter is subsequently passed to a strcpy() call, which copies the user-controlled string into a fixed-size stack buffer (aiStack_238). An unauthenticated attacker can exploit this by sending a crafted HTTP request with an overly long username string, leading to a crash (Denial of Service) or potentially arbitrary code execution. The vulnerability is reachable via the default web handler defined in the main execution flow.

## Affected products

- Tenda W3 Wireless Router v1.0.0.3(2204)

## Timeline

- 2026-03-15: 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/W3/R7WebsSecurityHandler](https://github.com/xhh0124/SemVulLLM/tree/main/W3/R7WebsSecurityHandler)

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