[Solved] Fixing Apache suexec and mod_fcgid: Error Reading Data from FastCGI Server

When running PHP applications under Apache using mod_fcgid combined with suexec privilege separation, web requests may suddenly abort with HTTP 500 Internal Server Errors and the following message in Apache error logs:

Error Message: End of script output before headers: php.fcgi • mod_fcgid: error reading data from FastCGI server

Root Cause

suexec enforces strict security checks on the FastCGI wrapper script and user directory:

1. The wrapper script and parent directories must be owned exclusively by the virtual server user and group—not root or apache.
2. File permissions cannot be group-writeable (chmod 755 is required, 775 or 777 causes instant suexec rejection).
3. The target script must reside strictly inside the compiled suexec document root (e.g. /home/user/public_html).

Resolution Steps

Inspect /var/log/httpd/suexec.log to reveal the exact permission violation, and enforce correct ownership:

# Fix permissions and ownership
chown -R user:user /home/user/fcgi-bin /home/user/public_html
chmod 755 /home/user/fcgi-bin/php.fcgi
chmod 755 /home/user/public_html

How to Install Virtualmin with Multiple PHP and MySQL Versions on CentOS 8

Deploying a production web hosting stack on CentOS 8 with Virtualmin requires modern multi-PHP support (allowing legacy applications to run PHP 5.6 or 7.2 while modern apps run PHP 7.4 or 8.0) and reliable database server management via Remi repositories.

Stack: CentOS 8 • Virtualmin 6.x • Remi Software Collections (SCL) • MySQL 8.0 • Multi-PHP

1. Fix Perl UTF-8 Locale Warnings

cat << 'EOF' > /etc/environment
LANGUAGE=en_US.utf8
LC_ALL=en_US.utf-8
LANG=en_US.utf8
LC_TYPE=en_US.utf8
EOF

2. Enable EPEL and Remi Repositories

dnf install epel-release -y
dnf install https://rpms.remirepo.net/enterprise/remi-release-8.rpm -y
dnf module reset php -y
dnf module enable php:remi-7.4 -y

3. Installing Parallel PHP Versions

dnf install php56-php-fpm php72-php-fpm php74-php-fpm php80-php-fpm -y

4. Install Virtualmin

wget http://software.virtualmin.com/gpl/scripts/install.sh
sh install.sh