Quick answers
- Is CVE-2026-36777 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36777 being exploited in the wild.
- How severe is CVE-2026-36777?
- Informational severity, with a CVSS score of 7.5, published 9 June 2026.
- Which products and versions are affected?
- Tenda W3 Wireless Router v1.0.0.3(2204).
- Is there a fix for CVE-2026-36777?
- 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-2026-36777 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-36777?
- Check whether you run Tenda W3 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 'formSetCfm' CGI handler of the Tenda W3 router. The vulnerability is located within the 'save_list_data' function, which is called when the 'funcname' parameter is set to 'save_list_data'. The root cause is an unsafe 'sprintf' call (sprintf(acStack_154, "%s.listnum", param_1)) that processes the user-controlled 'funcpara1' parameter without length validation. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request to the 'setcfm' endpoint, leading to a crash of the web service or the entire device (Denial of Service). While primarily a DoS risk, stack overflows of this nature may potentially allow for arbitrary code execution.
Affected products
- Tenda (Shenzhen Tenda Technology Co., Ltd) W3 Wireless Router v1.0.0.3(2204)
Timeline
- 2026-03-10: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure via GitHub repository
- 2026-06-09: advisory: NVD published date