Quick answers
- Is CVE-2026-36818 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36818 being exploited in the wild.
- How severe is CVE-2026-36818?
- Informational severity, published 9 June 2026.
- Which products and versions are affected?
- Tenda W20E v15.11.0.6.
- Is there a fix for CVE-2026-36818?
- 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-2026-36818 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-36818?
- Check whether you run Tenda W20E 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 'formAddWewifiWhiteUser' function within the Tenda W20E v15.11.0.6 firmware. The vulnerability is triggered when the 'wewifiWhiteUserInfo' HTTP parameter, retrieved via 'websGetVar', is processed using 'strncpy' without adequate bounds checking. Specifically, the code calculates the length of the input up to a newline character and copies it into a fixed-size destination buffer ('temp'). An attacker can exploit this by sending a long string followed by a newline character in a crafted HTTP request to the 'addWewifiWhiteUser' action, leading to a process crash or device instability. While the advisory focuses on Denial of Service, buffer overflows of this nature can sometimes lead to remote code execution.
Affected products
- Tenda (Shenzhen Tenda Technology Co., Ltd) W20E v15.11.0.6
Timeline
- 2026-03-19: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure
- 2026-06-09: advisory: NVD published date