This is in the Developer FAQ. It takes anywhere between 1 and 10 days. We attempt to review all plugins within 5 business days of submission, but the process takes as long as it takes, depending on the complexity of your plugin.

Your plugin review cannot be prioritized over others, to help us approve your plugin sooner, please ensure that you have read the Security chapter of the Plugin Handbook.

Our three most common reasons for not approving a plugin are:

• The plugin contains unescaped output: Learn about Escaping Data
• The plugin accepts unsanitized data: Learn about Sanitizing Data
• The plugin processes form data without a nonce: Learn about Nonces

If the code in your plugin falls into one of the above categories, your plugin will not be approved. The Plugins Team will refer you back to these Handbook pages, adding further delay to the review process.