What potential security risks should be considered when using data from $_POST in $_SESSION variables?

When using data from $_POST in $_SESSION variables, the main security risk to consider is the possibility of injection attacks. To mitigate this risk, it is important to sanitize and validate the data before storing it in the $_SESSION variable. This can be done by using functions like htmlspecialchars() or mysqli_real_escape_string() to prevent malicious code from being executed. 

// Sanitize and validate data from $_POST before storing it in $_SESSION
if(isset($_POST['input_field'])){
    $sanitized_data = htmlspecialchars($_POST['input_field']);
    $_SESSION['user_data'] = $sanitized_data;
}

Keywords

PHP $_POST $_SESSION security risks data validation

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