Software⏱️ 2 min read📅 2026-05-31

How to Fix: Invalid self signed SSL cert - "Subject Alternative Name Missing"

Invalid self signed SSL cert - "Subject Alternative Name Missing"

Quick Answer: Add the Subject Alternative Name extension to your self-signed certificate.

Chrome has started to flag self-signed SSL certificates as insecure, and in some cases, it may not work at all. This is because the browser requires a Subject Alternative Name (SAN) extension to specify the domain name or IP address for which the certificate is valid.

🔍 Why This Happens

  • [Cause]

🔧 Proven Troubleshooting Steps

Method 1: Adding a SAN Extension

  1. Step 1: Open your SSL certificate file in a text editor, such as Notepad or TextEdit.

Method 2: Using an Online Certificate Generator

  1. Step 1: Go to a reputable online certificate generator, such as DigiCert or GetPublicKey.

🎯 Final Words

By following these steps, you should be able to resolve the 'Invalid self signed SSL cert - Subject Alternative Name Missing' error in Chrome.

Did this fix your problem?

If not, try searching for specific error codes.

🔍 Search Error Database

❓ Frequently Asked Questions