Quick answers
- Is CVE-2026-36791 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36791 being exploited in the wild.
- How severe is CVE-2026-36791?
- Informational severity, with a CVSS score of 7.5, published 9 June 2026.
- Which products and versions are affected?
- Tenda O3 v1.0.0.5.
- Is there a fix for CVE-2026-36791?
- 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-2026-36791 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-36791?
- Check whether you run Tenda O3 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 Tenda O3v3 firmware version v1.0.0.5. The vulnerability is located within the 'save_list_data' function, where a user-controlled parameter (funcpara1) is passed to 'sprintf' without adequate length validation. Specifically, the 'acStack_154' buffer is overflowed when 'sprintf' constructs a string using the tainted input. An unauthenticated remote attacker can trigger this by sending an HTTP request with 'funcname' set to 'save_list_data' and an oversized 'funcpara1' value. While primarily identified as a Denial of Service (DoS) vector, stack overflows in this context may potentially allow for arbitrary code execution.
Affected products
- Tenda O3v3 v1.0.0.5
Timeline
- 2026-03-15: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure of vulnerability details
- 2026-06-09: advisory: NVD published CVE-2026-36791