Resolved Nginx HTTP3 cause invalid redirect on WordPress

[Paulo_o]

I have activated HTTP/3 support for nginx in a Plesk Obsidian 18.0.61 with OS Ubuntu 20.04.6 LTS.

However when a user loads any webpage using http3 there is a redirect error, and the user does not see the webpage. An example of this behaviour with curl:

1) Curl with HTTP/2 example:

HTTP/2 200
server: nginx
date: Thu, 13 Jun 2024 01:36:29 GMT
content-type: text/html
content-length: 341380
last-modified: Thu, 13 Jun 2024 01:00:02 GMT
vary: Accept-Encoding
etag: "666a4492-53584"
vary: Accept-Encoding, Cookie
cache-control: public, max-age=600
x-content-type-options: nosniff
x-frame-options: sameorigin
strict-transport-security: max-age=31536000
x-rocket-nginx-serving-static: HIT
accept-ranges: bytes


2) Curl with HTTP/3 example for the same page:

HTTP/1.1 301 Moved Permanently
server: nginx
date: Thu, 13 Jun 2024 01:38:39 GMT
content-type: text/html; charset=UTF-8
location: https:///
x-redirect-by: WordPress
alt-svc: h3=":443"; ma=86400
strict-transport-security: max-age=15768000; includeSubDomains
x-rocket-nginx-serving-static: MISS
x-content-type-options: nosniff
x-frame-options: sameorigin

Retrieving the headers over HTTP3 Wordpress is trying to redirect to an invalid URL "https:///". This not happens using only HTTP2.0 or /1.

Any Ideas how to solve this issue?

 

[AYamshanov]

Likely, it happens because of a different way of processing the HTTP_HOST variable when Nginx serves HTTP/3 requests.
See #2281 (QUIC: failed to get $http_host variable for http3 request) – nginx for the details. A workaround for a similar issue was discussed at Resolved - Issue with HTTP/3 Activation on WOLTLAB Forum Administration.

 

[Paulo_o]

Yes, adding

fastcgi_param HTTP_HOST $host;

/etc/nginx/fastcgi.conf seems to work. Thank you!