HTTP 525 – SSL Handshake Failed
(Cloudflare) The SSL/TLS handshake between Cloudflare and the origin server failed.
Common use case
Occurs when Cloudflare is configured for Full or Full (Strict) SSL mode but the origin's TLS configuration (cipher mismatch, missing SNI support, etc.) prevents a successful handshake.
History
A Cloudflare-specific extension.
Did you know?
It is usually a configuration problem rather than an outage - the origin server is up, but Cloudflare and it simply can't agree on TLS terms.