Question What is 15085 actualy fixing?

[nmdpa3]

Server operating system version

Ubuntu

Plesk version and microupdate number

18.0.71

When 18.0.72 was released last week, the immediate issue many faced was anysite that was pointing to a specific IP address instead of default site was not accessiable. In the forum, it was noted by a plesk community person that a bug was recognized and documeted as 15085. Today, when 18.0.72 Update #1 came out, 15085 was listed as a fix for the following:

Fixed the issue where, after adding specific WordPress plugins to a WordPress website, browsing the website resulted in an infinite redirect loop if that website was set as the default website for an IP address in Plesk. (PPPM-15085)

Not sure what WordPress Plugins had to do with any of this (as described in the fix statement above)?

So, is the actuall problem fixed or not?

We certianly do not want to install 18.0.72 or 18.0.72 Update #1 and introduce the problem for customer websites that we saw in testing the 18.0.72 update last week (something Plesk should have caught themselves in testing). The documentation on this fix seems to not even mention what was actually happening?

 

[Sebahat.hadzhi]

Hello, @nmdpa3 . The wording of the Change log is related to how the issue was initially reported, but the root cause is the same. If you are still experiencing any issues after the update, please open a new report and provide us with step-by-step instructions on how we can replicate it on our end for further investigation.

 

[Hideki.Oride]

Hello! @Sebahat.hadzhi
Me too!
Since the update to 18.0.72 #2 early this morning(2025/09/03 in Japan), accessing the web using the IP address assigned to the server results in an HTTP 400 error, and the page does not display.

OS: CentOS7
Plesk Version: Plesk Obsidian 18.0.72 Update #2
WEB Service: nginx proxy & apache
(When providing services exclusively through Apache, no error occurs.)

</var/log/nginx/access.log>
- - [03/Sep/2025:16:59:32 +0900] "GET / HTTP/1.1" 400 347 "-" "curl/7.29.0"


What should I do?

 

[Hideki.Oride]

My Plesk Server is not set default site on IP address.
Therefore, the variable `$ip_default_host` is not defined.

so, since $ip_default_host does not exist, the line `proxy_set_header Host $ip_default_host;` is not processed correctly.

/etc/nginx/plesk.conf.d/ip_default/

< This directory is File not found>

/etc/nginx/plesk.conf.d/server.conf

server {
listen 192.168.0.1:80;

location ^~ /plesk-site-preview/ {
proxy_pass http://127.0.0.1:8880
proxy_set_header Host plesk-site-preview.local;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_cookie_domain plesk-site-preview.local $host;
access_log off;
}

location / {
proxy_pass http://127.0.0.1:7080
proxy_set_header Host $ip_default_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}

SERVER IP ADDRESS ACCESS :

% curl --verbose -I http://192.168.0.1
* Trying 192.168.0.1:80...
* Connected to 192.168.0.1 (192.168.0.1) port 80
> HEAD / HTTP/1.1
> Host: 192.168.0.1
> User-Agent: curl/8.7.1
> Accept: */*
>
* Request completely sent off
< HTTP/1.1 400 Bad Request
HTTP/1.1 400 Bad Request
< Server: nginx
Server: nginx
< Date: Wed, 03 Sep 2025 08:31:17 GMT
Date: Wed, 03 Sep 2025 08:31:17 GMT
< Content-Type: text/html; charset=iso-8859-1
Content-Type: text/html; charset=iso-8859-1
< Connection: keep-alive
Connection: keep-alive
<

SERVER HOST NAME ACCESS :

% curl --verbose -I http://hello.example.jp
* Host hello.example.jp:80 was resolved.
* IPv6: (none)
* IPv4: 192.168.0.1
* Trying 192.168.0.1:80...
* Connected to hello.example.jp (192.168.0.1) port 80
> HEAD / HTTP/1.1
> Host: hello.example.jp
> User-Agent: curl/8.7.1
> Accept: */*
>
* Request completely sent off
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< Server: nginx
Server: nginx
< Date: Wed, 03 Sep 2025 08:31:31 GMT
Date: Wed, 03 Sep 2025 08:31:31 GMT
< Content-Type: text/html
Content-Type: text/html
< Content-Length: 1658
Content-Length: 1658
< Connection: keep-alive
Connection: keep-alive
< Last-Modified: Tue, 30 Jul 2024 06:57:39 GMT
Last-Modified: Tue, 30 Jul 2024 06:57:39 GMT
< ETag: "67a-61e717e473ec0"
ETag: "67a-61e717e473ec0"
< Accept-Ranges: bytes
Accept-Ranges: bytes

 

[Sebahat.hadzhi]

Thank you for the report, @Hideki.Oride. Please try running the following command as a temporary workaround:

plesk bin apache --listen-on-localhost false

 

[Sebahat.hadzhi]

The behavior was recognized as a new bug identified with ID PPPM-15108. It is expected for the fix to be introduced along the next release. Please let me know if the aforementioned workaround did not resolve the issue in your case.