# CVE-2026-5567: Tenda M3 buffer overflow in setAdvPolicyData

Source: https://junglewise.ai/threats/cve-2026-5567-tenda-m3-buffer-overflow-in-setadvpolicydata  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-05. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-5567 · Severity: high · CVSS 8.8 · Published 2026-04-05

A security vulnerability has been identified in the Tenda M3 Access Controller, a device used to manage wireless networks. An attacker can exploit this flaw to cause the device to crash or stop responding, leading to a denial of service. In some cases, this could allow for further unauthorized access or disruption of the managed network infrastructure.

Technologies: [Tenda M3](https://junglewise.ai/threats/technologies/m3), [Tenda M3 Firmware](https://junglewise.ai/threats/technologies/m3-firmware). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-5567 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5567 being exploited in the wild.

**How severe is CVE-2026-5567?** High severity, with a CVSS score of 8.8, published 5 April 2026.

**Which products and versions are affected?** Tenda M3 Access Controller 1.0.0.10.

**Is there a fix for CVE-2026-5567?** 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-2026-5567 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-5567?** Check whether you run Tenda M3, Tenda M3 Access Controller or Tenda M3 Firmware 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 'setAdvPolicyData' function of Tenda M3 firmware version 1.0.0.10, specifically within the 'sub_648D4' subroutine. The vulnerability is caused by an unsafe 'strncpy' operation where the length parameter is calculated from the position of a colon character in the user-controlled 'rebootTime' parameter without validating the destination buffer size. A remote attacker with low privileges can exploit this by sending a specially crafted POST request to '/goform/setAdvPolicyData'. Successful exploitation can lead to a crash of the web management service, device-wide denial of service (DoS), or potential remote code execution. A public exploit (PoC) is available.

## Affected products

- Tenda M3 Access Controller 1.0.0.10

## Timeline

- 2026-03-19: disclosed: Vulnerability details and PoC published on GitHub by researcher Moxxkidd.
- 2026-04-05: advisory: CVE-2026-5567 published.

## References

- [https://github.com/Moxxkidd/CVE/issues/2](https://github.com/Moxxkidd/CVE/issues/2)
- [https://vuldb.com/submit/782999](https://vuldb.com/submit/782999)
- [https://vuldb.com/vuln/355337](https://vuldb.com/vuln/355337)
- [https://vuldb.com/vuln/355337/cti](https://vuldb.com/vuln/355337/cti)
- [https://www.tenda.com.cn/](https://www.tenda.com.cn/)

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