520 error when accessing via Safari or make.com, no error when using Chrome or cURL

Hi there,

we do have a very puzzling problem. Accessing a URL using Safari or make.com results in a 520 error from Cloudflare, accessing the same URL from Chrome or cURL produces the correct result.

The reason for the 520 is that the request crashes the apache server on the origin server with a Segmentation Fault.

But accessing the origin server directly using Safari also returns the desired result.

This means putting Cloudflare in the pipeline changes something that makes the origin server crash.

The problem only happens when the URL reaches a certain length.

I have some URLs that show this but am not allowed to post them here by the Cloudflare Community forum. I also can’t post screenshots of them. How am I supposed to get support here?

URL 1 works in Safari and Chrome

  • redakted-

URL 2 works in Chrome but crashes the server in Safari

  • redakted-

The difference between those two URls is just a “1” at the end.

Both work in Safari and Chrome if I send them directly to the origin server and don’t crash the origin server. (I don’t want to expose that URL here)

Also, there is a Page Rule in Cloudflare that sets the Cache Level for apps.boinx.com to “ByPass” so the request and response shouldn’t be modified by Cloudflare at all as far as I understand it.

Any ideas?

Post them inside back ticks `like this` to give like this. (New users can’t post links due to spammers).

Thanks for the info. Here are the links for testing:

URL 1 works in Safari and Chrome


URL 2 works in Chrome but crashes the server in Safari


PS. The difference between URL 1 and 2 is just the last “1” character which brings the URL 2 over some threshold that seems to be the key in this mystery.