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CORS errors when disabling cache in developer tools

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Yann Soubeyrand
Yann Soubeyrand
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Hello,

When I open the developer tools (using F12) and I check the disable cache checkbox of the network tab, I get CORS errors saying that `Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://<my-resource>. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).`.

From my understanding, since the requests triggering the errors have the `Cache-Control` header set (due to the cache disabling), these requests do not qualify as simple requests (https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simple_requests). That’s why the server (AWS CloudFront) does not return CORS headers. However, I do not understand why Firefox did not send preflight requests (https://developer.mozilla.org/en-US/docs/Glossary/Preflight_request) in these cases.

Did I miss something? Or am I hitting a bug in Firefox?

Regards

Hello, When I open the developer tools (using F12) and I check the disable cache checkbox of the network tab, I get CORS errors saying that `Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://<my-resource>. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).`. From my understanding, since the requests triggering the errors have the `Cache-Control` header set (due to the cache disabling), these requests do not qualify as simple requests (https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simple_requests). That’s why the server (AWS CloudFront) does not return CORS headers. However, I do not understand why Firefox did not send preflight requests (https://developer.mozilla.org/en-US/docs/Glossary/Preflight_request) in these cases. Did I miss something? Or am I hitting a bug in Firefox? Regards

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