# CVE-2026-36784: Tenda O3 Wireless Router stack overflow in fromNetToolGet

Source: https://junglewise.ai/threats/cve-2026-36784-tenda-o3-wireless-router-stack-overflow-in-fromnettoolget  
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-2026-36784 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda O3 wireless router, used for long-range outdoor wireless networking, contains a security flaw in its web management interface. By sending a specially crafted web request, an attacker can crash the device's management service. This results in a denial-of-service, preventing administrators from managing the device and potentially disrupting network connectivity.

Technologies: [Tenda O3 Wireless Router](https://junglewise.ai/threats/technologies/o3). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-36784 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36784 being exploited in the wild.

**How severe is CVE-2026-36784?** Informational severity, with a CVSS score of 7.5, published 9 June 2026.

**Which products and versions are affected?** Tenda O3 Wireless Router v1.0.0.5(4180).

**Is there a fix for CVE-2026-36784?** 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-2026-36784 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-36784?** Check whether you run Tenda O3 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 'fromNetToolGet' CGI handler of the Tenda O3 router. The vulnerability is located in the 'fromNetToolGet' function, where the 'ip' HTTP parameter is retrieved using 'websGetVar' and subsequently copied into a fixed-size stack buffer ('acStack_12cc') using the unsafe 'strcpy' function without length validation. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request with an oversized 'ip' string. Successful exploitation leads to a process crash or device instability, resulting in a Denial of Service (DoS). The vulnerability was identified in firmware version v1.0.0.5(4180).

## Affected products

- Tenda O3 Wireless Router v1.0.0.5(4180)

## Timeline

- 2026-03-13: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure
- 2026-06-09: advisory: NVD publication date

## References

- [https://github.com/xhh0124/SemVulLLM/tree/main/O3/fromNetToolGet_ip](https://github.com/xhh0124/SemVulLLM/tree/main/O3/fromNetToolGet_ip)

## Related threats

- [Tenda O3 Wireless Router stack overflow in fromNetToolGet](https://junglewise.ai/threats/cve-2026-36783-tenda-o3-wireless-router-stack-overflow-in-fromnettoolget)
- [Tenda O3 Wireless Router stack overflow in fromVirtualSer](https://junglewise.ai/threats/cve-2026-36779-tenda-o3-wireless-router-stack-overflow-in-fromvirtualser)
- [Tenda O3 Wireless Router stack overflow in R7WebsSecurityHandler](https://junglewise.ai/threats/cve-2026-36778-tenda-o3-wireless-router-stack-overflow-in-r7webssecurityhandler)