← All Status Codes
523
Origin Is Unreachable
☁️ Cloudflare Critical Risk

📖 What Is HTTP 523?

Cloudflare-specific. Cloudflare could not reach the origin server. DNS resolution succeeded but no route to the origin exists.

🛡️ Security Implications

May indicate DNS hijacking if the origin IP has changed unexpectedly. Verify DNS records are correct.

🔍 Common Causes

Origin server IP changed but Cloudflare DNS not updated, hosting provider network outage, origin server moved.

🔧 How to Fix

Verify the origin IP in Cloudflare DNS settings matches your actual server IP. Check hosting provider status.

🖥️ How to Check

curl -I -o /dev/null -w "%{http_code}" https://example.com

🔗 Related Cloudflare Codes

520
Web Server Error
521
Web Server Is Down
522
Connection Timed Out
524
A Timeout Occurred
525
SSL Handshake Failed
526
Invalid SSL Certificate
530
Origin DNS Error
📚 Learn Web Security — Free Course