Quick answers
- Is CVE-2026-36819 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-36819 being exploited in the wild.
- How severe is CVE-2026-36819?
- 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-2026-36819?
- 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-2026-36819 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-36819?
- 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 Tenda W20E router firmware version v15.11.0.6. The vulnerability is located within the 'fromSetDhcpRules' function, specifically inside the 'modifyDhcpRule' sub-function. The 'bindMACAddr' HTTP parameter is retrieved via 'websGetVar' and subsequently passed to 'snprintf' with a fixed-size destination buffer of 0x2f bytes. An attacker can provide an overly long string (e.g., 888 characters) for the 'bindMACAddr' parameter to overflow the buffer. This can be exploited via a network-reachable HTTP request to the 'setDhcpRules' action, resulting in a process crash or device instability (Denial of Service).
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