# CVE-2026-36803: Tenda PW201A buffer overflow in qossetting

Source: https://junglewise.ai/threats/cve-2026-36803-tenda-pw201a-buffer-overflow-in-qossetting  
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-2026-36803 · Severity: info · CVSS 7.5 · Published 2026-06-09

A vulnerability exists in the Tenda PW201A wireless powerline adapter, a device used to extend network coverage through electrical wiring. An attacker can exploit this flaw to crash the device or make it unstable by sending a specially crafted web request. This results in a loss of internet connectivity and network services for users relying on the affected hardware.

Technologies: [Tenda PW201A](https://junglewise.ai/threats/technologies/pw201a). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-36803 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36803 being exploited in the wild.

**How severe is CVE-2026-36803?** Informational severity, with a CVSS score of 7.5, published 9 June 2026.

**Which products and versions are affected?** Tenda PW201A v1.0.5.

**Is there a fix for CVE-2026-36803?** 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-2026-36803 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36803?** Check whether you run Tenda PW201A 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_HTTPD binary of Tenda PW201A v1.0.5. The vulnerability is located in the qossetting function (offset 0x42e1c4), which is registered as a web form handler. The function retrieves the 'page' parameter using websGetVar and subsequently passes it to sprintf without length validation to populate a fixed-size stack buffer (acStack_120). An unauthenticated remote attacker can trigger this overflow by sending a crafted HTTP request with an excessively long string in the 'page' parameter, resulting in a process crash or device instability.

## Affected products

- Tenda PW201A v1.0.5

## Timeline

- 2026-03-17: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure of vulnerability details
- 2026-06-09: advisory: NVD published date

## References

- [https://github.com/xhh0124/SemVulLLM/tree/main/PW201A/qossetting](https://github.com/xhh0124/SemVulLLM/tree/main/PW201A/qossetting)

## Related threats

- [Tenda G0 and PW201A buffer overflow in Saveqqlist function](https://junglewise.ai/threats/cve-2026-36805-tenda-g0-and-pw201a-buffer-overflow-in-saveqqlist-function)
- [Tenda PW201A buffer overflow in SafeMacFilter](https://junglewise.ai/threats/cve-2026-36802-tenda-pw201a-buffer-overflow-in-safemacfilter)