Applicable to:
- Plesk for Linux
Symptoms
-
All websites show the error:
PLESK_INFO: 421 Misdirected Request
-
The following error message is logged in domain's log (Plesk > Domains > example.com > Logs):
CONFIG_TEXT: AH02032: Hostname default-203_0_113_2 (default host as no SNI was provided) and hostname www.example.com provided via HTTP have no compatible SSL setup
Cause
In recent Apache version, Apache team has released fixes for CVEs that affected Apache + nginx functionality: new changes do not allow Apache process requests from nginx without the server name (by default, nginx does not pass the server name through SNI when establishing a connection with a proxied HTTPS server).
This issue has been addresses in Plesk Obsidian 18.0.70 and later releases.
Resolution
Update Plesk Obsidian to the latest build.
Note: The hotfixes are compatible with the manual workaround. So, even for servers where manual solution is already applied, no extra steps are required after installing Plesk update.
Manual workaround for previous Plesk versions:
Add proxy_ssl_server_name, proxy_ssl_name and proxy_ssl_session_reuse directives in nginx configuration to make nginx pass the server name to Apache through TLS Server Name Indication (SNI) extension:
- Connect to the Plesk server via SSH.
-
Run the script (without any modifications):
# echo -e "proxy_ssl_server_name on;\nproxy_ssl_name \$host;\nproxy_ssl_session_reuse off;" > /etc/nginx/conf.d/fixssl.conf && systemctl restart nginx
Comments
Thanks Kuzma Ivanov
The described command didn't fix the issue on my server.
What seemed to help on my server was removing NGINX and installing it again.
Need to correct myself: only if NGNIX is not running, websites are reachable. Will keep it off, until Fix is available
"This configuration solved the issue, but now webmail.sitename.com is not opening."
We run our server on Strato. After we ran the above command, neither plesk nor server is accessible.
Thank you for providing this workaround / temporary fix!
For goodness sake. If you update the fix for an ongoing issue, add some notes to explain it! It looks like the 3rd parameter change added (but not highlighted) has fixed the issue with this only working for the first site visited, which many people have reported. This needs to be made clear for those still with an issue.
And add a important note about people posting “me too”. Anyone trying to follow updates on this is getting flooded with pointless replies saying it works for them, or others who clearly have a different issue.
If the patch was done before “Plesk Obsidian 18.0.71 Update 1”, should we remove the patch after the update?
If so, perhaps you could update this article.
I tested the 18.0.71.1 update on my Ubuntu 22.04 server AFTER having applied the manual patch yesterday. Everything still works, but it would be great to know if any steps need to be taken for those who had applied the manual patch before the update was published.
I updated Plesk to version 18.0.71, which is supposed to include the official fix for the
"421 Misdirected Request"issue caused by the recent Apache update.After the upgrade, I tried to remove the temporary workaround (the one adding
proxy_ssl_server_name on, etc. in/etc/nginx/conf.d/fixssl.conf) and restarted NGINX — but unfortunately, the 421 error came back right away.So for now, I've restored the patch, and everything is working fine again.
Even after updating to 18.0.71, the issue still seems to persist in some environments. I recommend keeping the patch in place for now until a more complete fix or further guidance is provided by Plesk.
Doesn't work for me, I used this script in WHM with the root user:
And the terminal only shows me the following message:
And when trying to browse the sites hosted on this server, the error continues:
Please help!
OS: AlmaLinux v8.10.0 STANDARD kvm
cPanel Version: 128.0.17
Hey Diego Gomez, the fix above is for Plesk! For cPanel you may have a look here:
https://support.cpanel.net/hc/en-us/articles/33553346450455-Websites-show-421-Misdirected-Request-error-while-using-EA-Nginx
after the update or apply the hotfix. My WorPress Website cannot present normarly. It's able to show the text but the style.css and picture file has show “301 Moved Permenatly” . Any one also facing this problem ?
Example : asiaton.com.my
have you check the permalinks in wordpress?
Looks like after performing the full sudo plesk repair web -y it is working, but still experiencing SSL issues. hopefully they will resolve soon
I'm experiencing the same issue—all websites hosted on Plesk are currently inaccessible.
When I navigate to Tools & Settings → Plesk → Updates to update to the latest version, the page keeps loading and eventually returns an “ERR_CONNECTION_TIMED_OUT” error.
Additionally, when I go to the Home page → Check for Updates, it only shows Plesk Obsidian 18.0.71 as available. However, according to the article, we need to update to 18.0.71.1 to resolve this issue.
Since this problem, everything is running unstable. Please help!
1. Shortly after the problem occurs, we have implemented the 'manual workaround'. It worked again.
2. Until the update to Plesk Obsidian 18.0.70.3 was released on July 18, 2025, it worked through the workaround. Then, all websites crashed every 15 to 30 minutes. A manual restart of the Apache service has to be performed every time there is a problem since then.
3. Updated to Plesk Obsidian 18.0.71.1. Now all websites have crashed. According to the log, due to this problem: AH00484: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting (https://support.plesk.com/hc/en-us/articles/12377660243351-Apache-keeps-going-down-on-a-Plesk-server-server-reached-MaxRequestWorkers-setting), for MPM Event, the entries were adjusted:
MaxRequestWorkers 400
ServerLimit 16
4. Some of the websites, seemingly at random, are now down for about 9 to 37 minutes every 15 minutes and then become accessible again (websites load slower than normal). I cannot find any relevant errors in the logs and no MaxRequestWorkers messages.
We obviously got hit with the same problems across all our servers and sites. I happened to see a notice about it at the time it happened - in the middle of the night. So, in panic mode, I started working with ChatGPT to try to fix it. This was before we had any information from Plesk, and before the above patch came around. ChatGPT suggested lots of command line things at that point - and none of it worked. Another problem for us was that our servers are AWS Lightsail servers. And the way that is set up with Plesk seems to overwrite a lot of config files automatically. So certain command line changes would just revert back. I was just running in circles, especially as my technical knowledge is pretty limited and I didn't know exactly what ChatGPT was doing and how to better guide it.
I then switched to Claude and it quickly found a solution that seems to be pretty stable thus far. Under the nginx settings for each domain, it suggested simply turning off “Proxy mode” until a stable solution is provided by Plesk. That has worked really well thus far across our servers and domains - requiring no command line modifications. All sites are behaving normally.
My fingers are still crossed that this doesn't blow up with new updates, but so far so good. Hopefully it will work for others.
Cheers.
My Server was hit with this. I run a bare metal server from ibm.com. I cannot access the server via SSH , FTP or the Plesk control Panel. Though in Plesk I can get to the Repair Kit. I do not pay for advanced support with IBM as I usually can correct errors. I created a ticket with IBM and they did run the command:
"echo -e "proxy_ssl_server_name on;\nproxy_ssl_name \$host;\nproxy_ssl_session_reuse off;" > /etc/nginx/conf.d/fixssl.conf && systemctl restart nginx"
Access was restored to the main website but I cannot access the Plesk Panel to make sure I am on a good version of the panel. How do I do this? No SSH access at all.
Running Ubuntu supplied by IBM as well IBM installed the Plesk Control Panel
same issue running aws cloudfront infront of apache.
update to plesk Plesk 18.0.71 Update 1 did not fix it.
I have Product: Plesk Obsidian 18.0.71 Update #1, last updated on July 19, 2025 06:26 AM
But if I restart the server, problems again.
Have to redo the manual fix:
echo -e "proxy_ssl_server_name on;\nproxy_ssl_name \$host;\nproxy_ssl_session_reuse off;" > /etc/nginx/conf.d/fixssl.conf && systemctl restart nginx
and then all OK …
Kuzma Ivanov please respond to:
All websites going down and up constantly
https://support.plesk.com/hc/en-us/articles/33500191748887/comments/33590356677783
This kb has become very noisy. if you have problems do not comment here, but go to the plesk forum. it is very disurbing that on one hand we have to follow the issue for updates and on the other hand reading all day long issues from users which do not solve the problem. so please go to the forum and seek for help there. thanks
how to fix this sh*t, when NOT using nginx? we're running aws cloudfront as a reverse proxy. every url that invalidates gets broken.
(421 Misdirected Request)
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