Quick answers
- Is CVE-2026-9431 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-9431 being exploited in the wild.
- How severe is CVE-2026-9431?
- High severity, with a CVSS score of 8.8, published 25 May 2026.
- Which products and versions are affected?
- Tenda F1202 1.2.0.20(408).
- Is there a fix for CVE-2026-9431?
- 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-2026-9431 attacked?
- It is attacked over the network, in device firmware.
- Am I affected by CVE-2026-9431?
- Check whether you run Tenda F1202 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 vulnerability exists in the 'httpd' binary of the Tenda F1202 router (version 1.2.0.20(408)). The issue resides in the 'fromPptpUserAdd' function within the '/goform/PptpUserAdd' (or '/goform/PPTPDClient') endpoint. When the 'opttype' parameter is set to 1, the 'username' parameter is processed by an 'sprintf' function call without adequate length validation, leading to a buffer overflow on the stack. A remote attacker with low privileges (authenticated) can exploit this by sending a specially crafted POST request containing an excessively long string. Successful exploitation can result in a denial of service (DoS) or remote code execution (RCE). A public exploit (PoC) is available.
Affected products
- Tenda F1202 1.2.0.20(408)
Timeline
- 2026-05-25: disclosed: Vulnerability reported via VulDB and NVD