Quick answers
- Is CVE-2026-36821 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36821 being exploited in the wild.
- How severe is CVE-2026-36821?
- Informational severity, with a CVSS score of 7.5, published 9 June 2026.
- Which products and versions are affected?
- Tenda W20E v15.11.0.6.
- Is there a fix for CVE-2026-36821?
- 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-2026-36821 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-36821?
- 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 vulnerability exists in the Tenda W20E router firmware version v15.11.0.6. The flaw is located within the 'formCropAndSetWewifiPic' function, where the 'picCropName' HTTP parameter is retrieved via 'websGetVar' and subsequently passed to 'sprintf' without adequate bounds checking. An unauthenticated remote attacker can exploit this by sending a crafted HTTP request containing an overly long string in the 'picCropName' parameter. Successful exploitation leads to a process crash or device instability, resulting in a Denial of Service (DoS). While the advisory focuses on DoS, stack overflows of this nature can sometimes be leveraged for remote code execution.
Affected products
- Tenda 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