# CVE-2026-19790: Tenda G0 stack buffer overflow in port mirror handler

Source: https://junglewise.ai/threats/cve-2026-19790-tenda-g0-stack-buffer-overflow-in-port-mirror-handler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-14. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-19790 · Severity: high · CVSS 8.8 · Published 2026-08-14

Tenda G0 routers contain a buffer overflow vulnerability in the web management interface's port mirroring configuration function. An attacker can remotely send a specially crafted request with an oversized portMirrorMirroredPorts parameter to crash the device or execute arbitrary code, compromising the router's availability and security.

Technologies: [Tenda G0](https://junglewise.ai/threats/technologies/g0). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-19790 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-19790 being exploited in the wild.

**How severe is CVE-2026-19790?** High severity, with a CVSS score of 8.8, published 14 August 2026.

**Which products and versions are affected?** Tenda G0 up to 20260625.

**Is there a fix for CVE-2026-19790?** 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-2026-19790 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-19790?** Check whether you run Tenda G0 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 formSetPortMirror function within the httpd web management interface (/goform/module endpoint). The vulnerability occurs because the portMirrorMirroredPorts parameter is read from user input and passed directly to sprintf() without length validation, writing into a fixed 256-byte stack buffer. An attacker can exploit this remotely by sending an HTTP request with a crafted portMirrorMirroredPorts value exceeding the buffer size. Successful exploitation can lead to memory corruption, denial of service, or arbitrary code execution. A patch is available and the exploit is publicly disclosed.

## Affected products

- Tenda G0 up to 20260625

## Timeline

- 2026-08-14: disclosed: Published on NVD
- 2026-08-14: other: Exploit publicly available on GitHub

## References

- [https://github.com/lipenghai/iot_bug/blob/main/Tenda/G0/1.md](https://github.com/lipenghai/iot_bug/blob/main/Tenda/G0/1.md)
- [https://vuldb.com/cve/CVE-2026-19790](https://vuldb.com/cve/CVE-2026-19790)

## Related threats

- [Tenda G0 buffer overflow in setPortMapping](https://junglewise.ai/threats/cve-2026-19792-tenda-g0-buffer-overflow-in-setportmapping)
- [Tenda G0 stack buffer overflow in addStaticRoute](https://junglewise.ai/threats/cve-2026-19791-tenda-g0-stack-buffer-overflow-in-addstaticroute)
- [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 G0 buffer overflow in formIPMacBindAdd](https://junglewise.ai/threats/cve-2026-36801-tenda-g0-buffer-overflow-in-formipmacbindadd)
- [Tenda G0 buffer overflow in formIPMacBindDel](https://junglewise.ai/threats/cve-2026-36800-tenda-g0-buffer-overflow-in-formipmacbinddel)