How to fix ssl error on Magento Open Source

Steps for Magento Open Source

1. SSL management is identical to Adobe Commerce self-hosted — handled at the server/hosting level, not inside the Magento admin panel.
2. Use your hosting control panel (cPanel/Plesk) or Let's Encrypt/Certbot on the command line to issue a certificate that covers all domain variants.
3. Run: `sudo certbot --nginx -d yourstore.com -d www.yourstore.com` (adjust for Apache if needed).
4. In Magento Admin → Stores → Configuration → Web, update Secure Base URL to use https:// with the correct domain.
5. Flush Magento cache after changes.

What is ssl error?

Every HTTPS website uses an SSL/TLS certificate to prove its identity to browsers and to encrypt the connection. The certificate must explicitly list the domain name (or names) it is allowed to protect. A "hostname mismatch" error means the certificate installed on your server was issued for a different domain than the one visitors are actually trying to reach — for example, the certificate covers "www.yourstore.com" but not "yourstore.com" (or vice versa), or it was issued for a completely different domain altogether. Browsers and security scanners treat this as a critical failure and refuse to establish a trusted connection.

When a hostname mismatch exists, most modern browsers display a full-page "Your connection is not private" warning before visitors can even see your store. This kills conversions — the majority of shoppers will leave immediately rather than click through a security warning. Google also uses HTTPS as a ranking signal and can demote or omit pages it cannot crawl securely. Beyond lost sales and rankings, transmitting payment and personal data over an untrusted connection is a serious security risk and may violate PCI DSS compliance requirements for accepting card payments. This maps directly to OWASP A02:2021 — Cryptographic Failures.

See the complete Ssl error guide for every platform and the full background.