Unable to upload file to the website hosted in Plesk when Imunify is present on the server: Request body no files data length is larger than the configured limit

Daniel Yordanov

Updated November 13, 2025 12:45

Plesk for Linux kb: technical ext: Imunify ext: modsec

Applicable to:

Plesk for Linux

Symptoms

Unable to upload a file to a website hosted in Plesk with the following error:

CONFIG_TEXT: 413 Request entity too large

CONFIG_TEXT: Request Entity Too Large
The requested resource
/upload-a-file/
does not allow request data with POST requests, or the amount of data provided in the request exceeds the capacity limit.
On uploading a big file via WordPress administrator interface, the following error is shown:

Unexpected response from the server. The file may have been uploaded successfully. Check in the Media Library or reload the page
The Web Application Firewall (ModSecurity) component is installed and active on the server
The Imunify extension for Plesk (aka Imunify360) is installed and active on the server
An error that is similar to the following can be found in the Apache error log /var/www/vhosts/example.com/logs/error_log:

CONFIG_TEXT: ModSecurity: Request body no files data length is larger than the configured limit (1048576).. Deny with code (413) [hostname "example.com"] [uri "/Backoffice/index.php"] [unique_id "YCK6aBTMZUZFIMPlEoLhpAAAABk"]

CONFIG_TEXT: 2023-01-22 13:40:52 Error 203.0.113.2 [client 203.0.113.2] ModSecurity: Request body (Content-Length) is larger than the configured limit (134217728). [hostname "example.com"] [uri "/wp-admin/async-upload.php"] [unique_id "ZbEVgLPF684lP2xTCxMAEwAAABg"], referer: https://example.com/wp-admin/media-new.php Apache error

Cause

The error is caused by the limit of the SecRequestBodyNoFilesLimit within the Imunify360 ruleset for ModSecurity being reached, which makes ModSecurity deny the upload action.

Resolution

Proceed to increase the resource necessary ModSecurity limits as follows:

Click on a section to expand

Globally on the server

Log in to the server via SSH.
Create the file zz_modsec2.conf:
- On CentOS/RHEL/CloudLinux:
  
  /etc/httpd/conf.d/zz_modsec2.conf
- On Debian and Ubuntu:
  
  /etc/apache2/conf.d/zz_modsec2.conf
and set the following in it with a text editor:

CONFIG_TEXT: <IfModule mod_security2.c>
SecRequestBodyLimit 546870912
SecRequestBodyNoFilesLimit 546870912
</IfModule>

Note: The Limit below is specified in Bytes and equals 512 Megabytes.
Restart Apache server:

On CentOS/RHEL/CloudLinux:

# systemctl restart httpd
On Debian and Ubuntu:

# systemctl restart apache2

By specific domain

Log in to Plesk
Go to Domains > example.com > Apache & Nginx Settings and set the following in both the Additional directives for HTTP and Additional directives for HTTPS fields:

Note: The Limit below is specified in Bytes and equals 512 Megabytes.

PLESK_INFO: <IfModule mod_security2.c>
SecRequestBodyLimit 546870912
SecRequestBodyNoFilesLimit 546870912
</IfModule>