Is CVE-2026-36809 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-36809 being exploited in the wild.

How severe is CVE-2026-36809?

Informational severity, with a CVSS score of 7.5, published 9 June 2026.

Is there a fix for CVE-2026-36809?

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-2026-36809 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-36809?

Check whether you run Tenda W15E 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.

CVE-2026-36809: Tenda W15E buffer overflow in formModifyWebAuthWhiteUser

CVE-2026-36809 · Severity: info · CVSS 7.5 · Published 2026-06-09

The Tenda W15E enterprise router, used to provide wireless connectivity and network management for small businesses, contains a security flaw in its web management interface. By sending a specially crafted web request to the device, an attacker can cause the router to crash or become unstable. This results in a denial-of-service, disrupting internet connectivity and business operations until the device is recovered.

Technologies: Tenda W15E. Vendors: Tenda.

Quick answers

Is CVE-2026-36809 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-36809 being exploited in the wild.
How severe is CVE-2026-36809?: Informational severity, with a CVSS score of 7.5, published 9 June 2026.
Which products and versions are affected?: Tenda W15E v15.11.0.10.
Is there a fix for CVE-2026-36809?: 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-2026-36809 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-36809?: Check whether you run Tenda W15E 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 'formModifyWebAuthWhiteUser' function within the Tenda W15E v15.11.0.10 firmware. The vulnerability is triggered when the 'webAuthWhiteID' parameter, retrieved via 'websGetVar', is passed to 'sprintf' or 'printf' to construct MIB strings (e.g., 'portal.whiteMACList%s') without proper bounds checking. An unauthenticated attacker can exploit this by sending a crafted HTTP request to the 'modifyWebAuthWhiteUser' action with an excessively long 'webAuthWhiteID' string. Successful exploitation leads to a process crash or device instability, resulting in a Denial of Service (DoS). Preconditions include setting 'webAuthWhiteUserType' to 'mac' and ensuring other required parameters like 'webAuthWhiteUser' are present.

Affected products

Tenda (Shenzhen Tenda Technology Co., Ltd) W15E v15.11.0.10

Timeline

2026-03-18: other: CVE request submitted to MITRE
2026-06-06: disclosed: Public disclosure of the vulnerability
2026-06-09: advisory: NVD published the CVE record

References

https://github.com/xhh0124/SemVulLLM/tree/main/W15E/formModifyWebAuthWhiteUser

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