External risk intelligence

Wavlink WL-WN530BE1-A Settings Export CGI Stack Buffer Overflow.

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-109109

The vulnerability affects a CGI component in a networking device (Wavlink router/access point). Such devices are commonly deployed as internet-facing gateways or edge network appliances, and the affected interface is accessible via web-based management, which is frequently exposed to the network to facilitate remote administration.

Memory Corruption

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Wavlink devices, specifically within the Settings Export CGI component. This issue allows for remote exploitation through a stack-based buffer overflow, potentially impacting network security and device integrity. Given that the exploit is publicly available, it presents a heightened risk of widespread misuse.

Remote attackers can overflow device memory.
This could compromise network edge devices.
Confirm relevance and exposure of Wavlink devices.

Attack Path

How an attacker could exploit the issue

An attacker can remotely trigger this vulnerability by sending a specially crafted HTTP request to the device. This request targets the Settings Export CGI component, specifically exploiting a weakness in how the `strcpy` function handles data within the `HTTP_COOKIE` or `X-Cmd` arguments. By overflowing a buffer, the attacker could potentially gain control and execute arbitrary code on the device.

No authentication or special access needed.
Triggered by manipulating HTTP cookie or command arguments.
Risk includes remote code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could impact the availability and integrity of the device's settings. An attacker who can send specially crafted HTTP requests to the device could trigger a stack-based buffer overflow by manipulating the `HTTP_COOKIE` or `X-Cmd` arguments in the `ExportAllSettings.cgi` function. This could lead to a denial-of-service condition or potentially allow for further unintended behavior when supported by the advisory.

Device settings could be affected.
Remote unauthenticated HTTP requests could trigger it.
Service disruption or unintended behavior may occur.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Wavlink WL-WN530BE1-A's Settings Export CGI component contains a critical stack-based buffer overflow vulnerability, exploitable remotely via HTTP. Given the public exploit and the nature of networking devices, infrastructure and network security teams should prioritize identifying and assessing affected devices, especially those exposed externally. The immediate next step is to confirm all instances of this device within the environment and evaluate their business criticality and exposure.

Infrastructure and Security teams own remediation.
Verify external reachability and asset criticality first.
Plan vendor coordination and risk reduction actions.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is the Wavlink WL-WN530BE1-A?

The Wavlink WL-WN530BE1-A is a networking device typically utilized as a wireless router or access point to provide internet connectivity and manage local network traffic. These devices often include web-based management interfaces that allow administrators to configure settings and export system data, which is the specific functionality involved in this security issue.

What is a stack-based buffer overflow in CVE-2026-109109?

This is a memory corruption weakness classified as CWE-121. It occurs when a program writes more data to a specific memory area, called the stack, than it can hold. In this case, the device's software uses the 'strcpy' function insecurely while processing settings, allowing incoming data to overwrite adjacent memory, which can lead to unintended execution or system instability.

How can an attacker trigger this vulnerability?

An attacker triggers this by sending a crafted HTTP request to the device's ExportAllSettings.cgi component. Specifically, manipulating the HTTP_COOKIE or X-Cmd arguments initiates the buffer overflow. Notably, this process does not require the attacker to have authentication or any prior special access to the device to attempt the manipulation.

Is my device at risk if it is not internet-facing?

Halo Surface Signal indicates that because this vulnerability affects a management component on a networking device, it is commonly exposed. While the threat is most urgent for internet-facing gateways, any device reachable on your internal network could still be targeted by an attacker who has already gained a foothold elsewhere in your environment.

What should I do if I use this Wavlink device?

Prioritize identifying all instances of the WL-WN530BE1-A within your environment. Once identified, evaluate the business criticality and network exposure of these assets. Since a public exploit exists, you should immediately assess whether you can restrict access to the device's web management interface to prevent unauthorized HTTP requests until you can plan further risk reduction.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.