Content Security Policy error in Vercel deployment

Oct 13, 2025 by leolavanderia.com.br 67 views

Introduction

As a developer, deploying a server to Vercel can be a seamless experience. However, sometimes, you may encounter errors that can be frustrating to resolve. One such error is the Content Security Policy (CSP) error in Vercel deployment. In this article, we will delve into the world of CSP, understand the error, and provide a step-by-step guide to resolve it.

What is Content Security Policy (CSP)?

Content Security Policy (CSP) is a security feature that helps prevent cross-site scripting (XSS) attacks by specifying which sources of content are allowed to be executed within a web page. It is a critical security measure that helps protect users from malicious scripts and other types of attacks.

What is a Content Security Policy Error in Vercel Deployment?

A Content Security Policy error in Vercel deployment occurs when the Vercel platform detects a script or resource that violates the Content Security Policy. This can happen when a script or resource is loaded from an unauthorized source, or when the script or resource is not properly configured to follow the CSP rules.

Understanding the Error Message

The error message you provided is:

Refused to load the script 'https://vercel.live/_next-live/feedback/feedback.js' because it violates the following Content Security Policy directive: "script-src 'self'".

This error message indicates that the script https://vercel.live/_next-live/feedback/feedback.js is trying to load from an unauthorized source, which is not allowed by the CSP policy.

Resolving the Content Security Policy Error in Vercel Deployment

To resolve the Content Security Policy error in Vercel deployment, you need to understand the CSP policy and configure your application to follow the rules. Here are the steps to resolve the error:

Step 1: Understand the CSP Policy

The CSP policy is defined in the Content-Security-Policy header of your application. You can find this header in the next.config.js file of your Next.js application.

module.exports = {
  // ...
  headers: () => {
    return [
      {
        source: '/_next/*',
        headers: [
          {
            key: 'Content-Security-Policy',
            value: "script-src 'self'; object-src 'self';",
          },
        ],
      },
    ];
  },
};

In this example, the CSP policy is set to allow scripts and objects from the same origin ('self').

Step 2: Configure the CSP Policy

To resolve the error, you need to configure the CSP policy to allow the script https://vercel.live/_next-live/feedback/feedback.js. You can do this by adding the following line to the Content-Security-Policy header:

module.exports = {
  // ...
  headers: () => {
    return [
      {
        source: '/_next/*',
        headers: [
          {
            key: 'Content-Security-Policy',
            value: "script-src 'self' https://vercel.live/_next-live/feedback; object-src 'self';",
          },
        ],
      },
    ];
  },
};

In this example, the CSP policy is updated to allow scripts from the same origin ('self') and from the https://vercel.live/_next-live/feedback origin.

Step 3: Verify the CSP Policy

After configuring the CSP policy, you need to verify that it is working correctly. You can do this by checking the Content-Security-Policy header in the response of your application.

curl -s -I https://your-app.vercel.app | grep Content-Security-Policy

This command will display the Content-Security-Policy header in the response of your application.

Conclusion

In this article, we discussed the Content Security Policy error in Vercel deployment and provided a step-by-step guide to resolve it. We understood the CSP policy, configured the policy to allow the script, and verified the policy. By following these steps, you can resolve the Content Security Policy error in Vercel deployment and ensure the security of your application.

Additional Resources

Frequently Asked Questions

Q: What is Content Security Policy (CSP)? A: Content Security Policy (CSP) is a security feature that helps prevent cross-site scripting (XSS) attacks by specifying which sources of content are allowed to be executed within a web page.
Q: What is a Content Security Policy error in Vercel deployment? A: A Content Security Policy error in Vercel deployment occurs when the Vercel platform detects a script or resource that violates the Content Security Policy.
Q: How do I resolve the Content Security Policy error in Vercel deployment? A: To resolve the Content Security Policy error in Vercel deployment, you need to understand the CSP policy, configure the policy to allow the script, and verify the policy.
Content Security Policy Error in Vercel Deployment: A Comprehensive Q&A Guide ================================================================================

Introduction

Q&A: Content Security Policy Error in Vercel Deployment

Q: What is Content Security Policy (CSP)?

A: Content Security Policy (CSP) is a security feature that helps prevent cross-site scripting (XSS) attacks by specifying which sources of content are allowed to be executed within a web page.

Q: What is a Content Security Policy error in Vercel deployment?

A: A Content Security Policy error in Vercel deployment occurs when the Vercel platform detects a script or resource that violates the Content Security Policy.

Q: How do I resolve the Content Security Policy error in Vercel deployment?

A: To resolve the Content Security Policy error in Vercel deployment, you need to understand the CSP policy, configure the policy to allow the script, and verify the policy.

Q: What is the purpose of the Content Security Policy (CSP) header?

A: The Content Security Policy (CSP) header is used to specify which sources of content are allowed to be executed within a web page. It helps prevent cross-site scripting (XSS) attacks by restricting the execution of scripts and other types of content.

Q: How do I configure the Content Security Policy (CSP) header in Next.js?

A: To configure the Content Security Policy (CSP) header in Next.js, you need to add the following code to your next.config.js file:

module.exports = {
  // ...
  headers: () => {
    return [
      {
        source: '/_next/*',
        headers: [
          {
            key: 'Content-Security-Policy',
            value: "script-src 'self'; object-src 'self';",
          },
        ],
      },
    ];
  },
};

Q: What is the difference between 'self' and 'unsafe-inline' in the Content Security Policy (CSP) header?

A: 'self' refers to the current origin, while 'unsafe-inline' refers to inline scripts and styles. Using 'unsafe-inline' can increase the risk of XSS attacks, while using 'self' can help prevent such attacks.

Q: How do I verify the Content Security Policy (CSP) header in Vercel deployment?

A: To verify the Content Security Policy (CSP) header in Vercel deployment, you can use the following command:

curl -s -I https://your-app.vercel.app | grep Content-Security-Policy

This command will display the Content Security Policy (CSP) header in the response of your application.

Q: What are the benefits of using Content Security Policy (CSP) in Vercel deployment?

A: The benefits of using Content Security Policy (CSP) in Vercel deployment include:

Improved security: CSP helps prevent cross-site scripting (XSS) attacks by restricting the execution of scripts and other types of content.
Better performance: CSP can help improve the performance of your application by reducing the number of requests made to external sources.
Increased flexibility: CSP allows you to specify which sources of content are allowed to be executed within a web page, giving you more control over the security and performance of your application.

Conclusion

In this article, we discussed the Content Security Policy error in Vercel deployment and provided a comprehensive Q&A guide to help you resolve it. We covered topics such as the purpose of the Content Security Policy (CSP) header, how to configure the header in Next.js, and how to verify the header in Vercel deployment. By following this guide, you can ensure the security and performance of your application and prevent cross-site scripting (XSS) attacks.

Additional Resources

Frequently Asked Questions

Q: What is Content Security Policy (CSP)? A: Content Security Policy (CSP) is a security feature that helps prevent cross-site scripting (XSS) attacks by specifying which sources of content are allowed to be executed within a web page.
Q: What is a Content Security Policy error in Vercel deployment? A: A Content Security Policy error in Vercel deployment occurs when the Vercel platform detects a script or resource that violates the Content Security Policy.
Q: How do I resolve the Content Security Policy error in Vercel deployment? A: To resolve the Content Security Policy error in Vercel deployment, you need to understand the CSP policy, configure the policy to allow the script, and verify the policy.