# CVE-2026-51844: Tenda AC7 stack buffer overflow in AdvSetMacMtuWan

Source: https://junglewise.ai/threats/cve-2026-51844-tenda-ac7-stack-buffer-overflow-in-advsetmacmtuwan  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-19. Updated: 2026-06-21  
License: CC BY 4.0 with a link back

CVE-2026-51844 · Severity: info · CVSS 9.8 · Published 2026-06-19

A vulnerability exists in the Tenda AC7 router, a device used to provide wireless internet access. An attacker can send a specially crafted request to the router's management interface to crash the device or potentially take full control of it. This could lead to a total loss of internet connectivity or allow an unauthorized user to monitor network traffic.

Technologies: [Tenda Ac7](https://junglewise.ai/threats/technologies/ac7). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-51844 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-51844 being exploited in the wild.

**How severe is CVE-2026-51844?** Informational severity, with a CVSS score of 9.8, published 19 June 2026.

**Which products and versions are affected?** Tenda Ac7 v15.03.06.44.

**Is there a fix for CVE-2026-51844?** 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-2026-51844 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-51844?** Check whether you run Tenda Ac7 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 AC7 router firmware version v15.03.06.44. The vulnerability is located in the 'check_param_changed' method, which processes the 'cloneType' parameter from the '/goform/AdvSetMacMtuWan' interface. The application uses the unsafe 'strcpy' function to copy user-supplied input into a fixed-size stack buffer without proper bounds checking. A remote attacker can exploit this by sending a crafted POST request to overwrite the stack, potentially leading to denial-of-service (DoS) or arbitrary code execution (RCE). While the advisory does not explicitly state authentication requirements, the PoC includes a password cookie, suggesting administrative access may be required depending on the device configuration.

## Affected products

- Tenda AC7 v15.03.06.44

## Timeline

- 2026-04-30: disclosed: Initial discovery and report by KDEV
- 2026-06-19: advisory: CVE published to NVD dataset

## References

- [https://www.kdev.site/cve-request_006/](https://www.kdev.site/cve-request_006/)

## Related threats

- [Tenda AC7 stack overflow in /goform/AdvSetMacMtuWan](https://junglewise.ai/threats/cve-2026-51846-tenda-ac7-stack-overflow-in-goform-advsetmacmtuwan)
- [Tenda AC7 stack buffer overflow in AdvSetMacMtuWan](https://junglewise.ai/threats/cve-2026-51845-tenda-ac7-stack-buffer-overflow-in-advsetmacmtuwan)
- [Tenda AC7 stack buffer overflow in AdvSetMacMtuWan](https://junglewise.ai/threats/cve-2026-51843-tenda-ac7-stack-buffer-overflow-in-advsetmacmtuwan)
- [A flaw has been found in Tenda AC7 15.03.06.44. Affected by this issue is the function fromSetSysTime of the file…](https://junglewise.ai/threats/cve-2026-4974-a-flaw-has-been-found-in-tenda-ac7-15-03-06-44-affected-by-this)
- [A vulnerability was determined in Tenda AC7 15.03.06.44. This affects an unknown function of the file…](https://junglewise.ai/threats/cve-2025-11586-a-vulnerability-was-determined-in-tenda-ac7-15-03-06-44-this)