External risk intelligence

Flex QR Code Generator Plugin Arbitrary File Upload Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-10041

The vulnerability exists in a WordPress plugin. WordPress sites are web applications typically deployed as public-facing services. Because the plugin functionality is part of the web-accessible site, the vulnerable code path is commonly exposed to the public internet.

Unrestricted File Upload

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

This advisory concerns a critical vulnerability in the Flex QR Code Generator WordPress plugin. The flaw allows unauthenticated attackers to upload arbitrary files to the server, potentially enabling them to execute malicious code remotely. The main concern is to confirm if this plugin is in use and if so, to assess the exposure.

File upload flaw in a WordPress plugin.
Critical risk of remote code execution.
Confirm plugin usage and assess exposure.

Attack Path

How an attacker could exploit the issue

An attacker can upload a malicious file to a WordPress site by exploiting a flaw in the QR code generator plugin. This occurs because the plugin does not properly check the types of files being uploaded. If successful, this could allow an attacker to execute arbitrary code on the server.

Unauthenticated access to the site is required.
Uploading a malicious file to the server triggers the vulnerability.
Risk of remote code execution on the server.

Live Threat

Current exploitation, exposure, and threat context

The Flex QR Code Generator plugin for WordPress could allow unauthenticated attackers to upload arbitrary files to the server. This could potentially lead to remote code execution if the uploaded file is a script that can be executed.

Arbitrary file uploads to the server.
Unauthenticated users can upload files.
Server compromise through code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the Flex QR Code Generator plugin affects WordPress sites, making them susceptible to arbitrary file uploads and potential remote code execution. Action is required by teams responsible for WordPress environments. The initial step should involve identifying all instances of the affected plugin, assessing their reachability and business criticality, and confirming the accountable owner for remediation planning.

WordPress administrators own this issue.
Verify plugin presence and reachability.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Flex QR Code Generator plugin?

It is a WordPress extension designed to help site administrators automatically create and manage QR codes for their pages or posts. By adding this plugin, a site gains the capability to generate graphical codes that users can scan to quickly access links or information. It simplifies the integration of QR technology directly into the WordPress dashboard, allowing non-technical users to manage these assets without custom code.

What does CVE-2025-10041 mean for security?

This vulnerability is classified as CWE-434, which refers to Unrestricted Upload of File with Dangerous Type. In plain terms, the plugin fails to verify the file type being uploaded to the server. Because the plugin blindly accepts files, an attacker can bypass security checks to upload malicious scripts. This weakness is dangerous because, if successful, it allows the attacker to execute unauthorized commands on the underlying server.

How is this vulnerability triggered?

The flaw is triggered when an attacker interacts with the specific vulnerable function used for saving QR codes. The exploit does not require the attacker to have an existing user account or administrative privileges on the site. However, simply visiting the site does not trigger the bug; the attacker must actively send a crafted file upload request that the plugin processes, creating a path for the malicious file to land on the server.

Why should I care if my site is affected?

Halo Surface Signal indicates that because this plugin is a component of a web-accessible WordPress site, it is inherently likely to be exposed to the public internet. Since the vulnerability allows unauthenticated access, any site running the plugin is reachable by remote attackers globally. If your site is accessible to the public, it faces a higher probability of being targeted compared to internal-only tools.

How do I respond to this threat?

Your first step is to inventory your WordPress environments to identify if the Flex QR Code Generator is installed. Once you have identified all instances, determine which sites are reachable from the internet and prioritize them for remediation. Coordinate with the owners of those specific instances to plan your next steps, such as disabling the plugin or removing it entirely until a verified update is available.

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.