Resolve Cloudflare Error 526: Service Unavailable

Cloudflare, a renowned content delivery network (CDN) and web application firewall, plays a pivotal role in shielding websites from diverse threats like DDoS attacks and malicious bots. Its function as a proxy, bridging your website’s origin server and its visitors, is crucial for both security and performance.

Encountering Cloudflare Error 526: Service Unavailable can be a common yet frustrating issue for website administrators. This error signifies a disruption in the connection between Cloudflare and your origin server, typically caused by problems with the SSL certificate. Promptly addressing this error is essential for restoring the normal functioning of your website.

Understanding Error 526: Service Unavailable

At the heart of Error 526 lies the issue of invalid SSL certificates on your origin server. Cloudflare’s role in proxying traffic necessitates an SSL handshake with your server. However, this process stumbles if your SSL certificate is expired, revoked, or improperly configured.

This error often arises when Full SSL (Strict) mode is active in your Cloudflare SSL settings. This mode demands valid SSL certificates on both ends – Cloudflare and your origin server.

Identifying and Addressing Error 526 Causes

To effectively resolve Error 526, it’s crucial to identify its root cause. Here are some steps to guide you through this process:

  1. Examine your SSL certificate’s expiration date: Renew it promptly if it has expired.
  2. Check the Common Name (CN) and Subject Alternative Names (SANs): Ensure they align with your domain name.
  3. Certificate Authentication: Verify that your certificate is authenticated by a recognized certificate authority (CA).
  4. Search for revocation messages: These could be linked to your certificate’s serial number.
  5. Consider disabling Full SSL (Strict) mode: This is a temporary measure if your certificate is otherwise valid.

Typically, Error 526 can be resolved by either renewing an expired certificate or rectifying any mismatches in domain names.

Resolving Error 526: Renewing SSL Certificates

If your certificate is found to be expired, revoked, or invalid, follow these steps to renew it:

  1. Acquire a new SSL certificate from a reputable CA such as Comodo, Digicert, or Let’s Encrypt.
  2. Install the new certificate and private key on your origin server.
  3. Update your server’s SSL binding to incorporate the new certificate.
  4. Restart related services like nginx, Apache, or IIS to implement the changes.

Ensure the certificate’s validity period and domain name are correct post-renewal. This typically resolves most instances of Error 526.

For further insights into dealing with Cloudflare errors, explore WordaThemes’ guides on Cloudflare Error 524 and Cloudflare Error 530. These resources offer comprehensive solutions to common Cloudflare issues, enhancing your website’s performance and security.

Verifying SSL Certificate Validation

Before enabling Strict SSL again, verify Cloudflare can validate your origin server certificate:

  • Go to “SSL/TLS” under the “Network” tab in your Cloudflare dashboard.
  • Check the validation status – it should show “Certificate is Valid”.
  • Review the issuer name to confirm it’s from a trusted CA.

This validation test ensures any SSL issues are fully resolved before re-enabling Strict SSL mode.

Modifying Cloudflare SSL Settings

If your certificate is actually valid, modify your Cloudflare SSL settings:

  • Temporarily switch from “Full (Strict)” SSL to “Full” SSL.
  • Alternatively, use the more flexible “Flexible SSL”.
  • Retry connecting to confirm Error 526 is now resolved.
  • Later, re-enable Strict SSL after any underlying issues are fixed.

Adjusting your SSL settings provides a workaround while you investigate the root cause.

Other Potential Troubleshooting Steps

In rare cases, Error 526 may persist due to unrelated origin server or network issues. Some troubleshooting tips include:

  • Checking for server configuration changes like disabled HTTPS bindings.
  • Testing network connectivity between Cloudflare and your origin server.
  • Confirming your firewall or ISP allows traffic on standard HTTPS ports.

Address any such issues before re-enabling Strict SSL to avoid future occurrences of Error 526.


Cloudflare Error 526 most commonly stems from invalid SSL certificates on your origin server. Renewing any expired or misconfigured certificates typically resolves this issue quickly.

Alternatively, adjusting your Cloudflare SSL settings can get your site back online while you address the root cause. Take proactive measures like monitoring certificate validity to prevent future downtime. With the right troubleshooting steps, you can swiftly eliminate Error 526 and restore your website’s accessibility.


What are the main causes of Error 526?

The primary triggers for Error 526 are expired, revoked, or incorrectly configured SSL certificates on your origin server. This prevents Cloudflare from completing the SSL handshake to proxy traffic.

How can I prevent future occurrences of Error 526?

Proactively renew your SSL certificates before they expire and set calendar reminders for renewal. Validate that all domain names match before deploying new certificates. Enable Certificate Transparency monitoring to check for potential revocations.

Does Error 526 mean my website was hacked?

No, Error 526 itself does not imply a security compromise. It is typically caused by routine certificate issues that are easily fixed by renewing or reconfiguring the certificates.

What should I do if my certificate is valid but Error 526 persists?

Verify Cloudflare can validate the certificate correctly under your SSL settings. Check for other problems like server misconfigurations, network disruptions, or incorrectly set domain names in Cloudflare. Adjust your SSL mode to Flexible SSL as a temporary workaround.

When should I re-enable Strict SSL mode after fixing Error 526?

Only re-enable Full SSL (Strict) after confirming Cloudflare validates your origin certificate correctly and any other issues are resolved. This prevents immediate recurrence of Error 526.

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