← All Status Codes
525
SSL Handshake Failed
☁️ Cloudflare High Risk

📖 What Is HTTP 525?

Cloudflare-specific. The SSL/TLS handshake between Cloudflare and the origin server failed. Certificate mismatch or expired certificate.

🛡️ Security Implications

SSL failures can indicate certificate expiration, misconfiguration, or potential MITM attack on the origin connection.

🔍 Common Causes

Expired origin SSL certificate, certificate hostname mismatch, unsupported TLS version, misconfigured SSL on origin.

🔧 How to Fix

Renew the origin SSL certificate. Ensure the certificate matches the hostname. Enable TLS 1.2+ on the origin server.

🖥️ 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
523
Origin Is Unreachable
524
A Timeout Occurred
526
Invalid SSL Certificate
530
Origin DNS Error
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