Description

The HTTP response status code 526 Invalid SSL Certificate is an unofficial HTTP status code specific to Cloudflare.

The 526 error occurs when Cloudflare cannot validate the SSL certificate on the origin web server. This typically happens when:

• The SSL certificate on the origin is self-signed and Cloudflare's SSL mode is set to Full (Strict).
• The certificate has expired.
• The certificate's hostname does not match the origin's hostname.
• The certificate is not trusted by a public Certificate Authority.

See Also

• Cloudflare docs
• Full Strict SSL