If you’re using Cloudflare as a content delivery network, you may have encountered the dreaded Error 526: Invalid SSL Certificate. This error occurs when Cloudflare is unable to establish a secure connection between your visitor and your origin web server due to an invalid SSL certificate. It’s a Cloudflare-specific error that can be frustrating to deal with, but fortunately, it’s also fixable.
In this article, we’ll dive into the causes of Error 526 and provide you with step-by-step instructions on how to fix it. Whether you’re a technical user or not, we’ll break it down in a way that’s easy to understand.
Understanding Cloudflare and SSL Certificates
Before we jump into fixing the error, let’s take a closer look at Cloudflare and SSL certificates. Cloudflare acts as a gateway between a user and a website server, providing a variety of performance and security benefits. One of these benefits is SSL encryption, which helps protect data exchanged between the user and the web server.
Cloudflare uses two SSL/TLS certificates: one provided by Cloudflare and one by the origin server. The Cloudflare certificate is the first one shown in the browser when visiting the website, while the origin server’s certificate protects data exchanges between the server and Cloudflare.
The Full (Strict) SSL option ensures a secure connection between both the visitor and Cloudflare domain, as well as the Cloudflare and origin web server connections. This is where the SSL certificate validation comes into play.
Causes of Error 526
Error 526 occurs when either the certificate provided by Cloudflare or by the origin server fails to establish a secure connection. This generally happens when:
- Cloudflare cannot validate the SSL certificate at your origin web server
- Full SSL (Strict) SSL is set in the Cloudflare SSL/TLS app.
How to Fix Error 526
Now that we understand the causes of Error 526, let’s get into how to fix it. Here are the steps you can take:
- Change the SSL mode to Full instead of Full (Strict) from the Overview tab of Cloudflare SSL/TLS section for the particular domain.
- Verify that the origin web server’s SSL certificates are not expired, revoked, or self-signed.
- Ensure that the requested domain name and hostname are in the certificate’s Common Name or Subject Alternative Name.
- Temporarily pause Cloudflare and cross-check the certificate with any SSL verification sites like https://www.sslshopper.com to verify that no issues exist with the origin SSL certificate.
- Install a proper SSL certificate signed by a Certificate Authority if the origin server is using an expired, revoked, or self-signed certificate.
In summary, Error 526 is a Cloudflare-specific error that occurs when Cloudflare is unable to validate the server’s SSL/TLS certificate. By following the steps above, you can fix the error and ensure a secure connection between your visitors and your web server. Remember to keep your SSL certificates up to date and properly signed by a Certificate Authority to avoid encountering this error in the future.