How to fix the "cURL error 60: SSL certificate problem" WordPress issue

From 30th September 2021, WordPress sites with Let's Encrypt certificates began experiencing SSL certificate errors when making HTTP API requests. This affects various WordPress functions including:

• WordPress core updates
• Plugin updates
• Third-party API integrations (e.g., TinyPNG, payment gateways)
• Any plugin using WordPress's HTTP API

Error message

cURL error 60: SSL certificate problem: certificate has expired

Fixes

Option 1: Update WordPress

You should be able to update WordPress to the latest version which in most cases will fix the issue. If you're unable to update WordPress through the admin dashboard, you may instead reinstall the core WordPress files through CLI which will update your installation. We do have guidance on doing this here.

Option 2: Manual Fix (if updating in option 1 fails)

If the WordPress update is still failing, you may manually fix the issue through the following steps.

1. Download the latest certificate bundle:
   1. Visit: https://curl.se/ca/cacert.pem
   2. Save the file to your computer
2. Replace WordPress certificate file:
   1. Navigate to /wp-includes/certificates/ca-bundle.crt on your hosting service file manager. If needed, we have guidance on using the cPanel File Manager here.
   2. Replace the contents with the downloaded cacert.pem content
   3. Done!

Test it works

Try updating a plugin or check for WordPress updates. The errors should be gone.