SSL Certificate Mismatch - Web App

Question

SSL Certificate Mismatch - Web App

Paul Olson 0

I am running a web application on a Linux B2 App Service Plan. In the Azure Portal, I added a custom domain, using a SNI SLL binding. I added the appropriate CNAME and TXT record to my DNS. The verification was successful. When I go to the website https://www.olievortex.com, I get a SSL mismatch error. The SSL Certificate is for *.azurewebsites.net, not www.olievortex.com. The diagnostics also confirms there is a SSL mismatch. Not sure where to go with this. It seems something under the hood is broken.

Siva Nair 1,475 Reputation points Microsoft External Staff

2025-04-30T03:09:09.9566667+00:00
Hi Paul Olson

Please check that the SSL certificate you have configured in Azure App Service is correctly bound to your custom domain (www.olievortex.com). As you mentioned your application is defaulting to the *.azurewebsites.net certificate instead of the one linked to your custom domain.

Double-check your DNS settings. Make sure that the CNAME records for your custom domain are pointing to the correct Azure endpoint and that your TXT verification records are configured properly.

Sometimes the App Service may not sync immediately with the new certificate. You can force a sync by going to the Azure portal:

Navigate to App Service Certificates.

Select your certificate.

Click on Rekey and Sync, then choose Sync.

check that the TLS certificate installed corresponds exactly to the CNAME being used (e.g., www.olievortex.com). If there’s any inconsistency, it could lead to SSL errors.

If you are routing traffic through an Application Gateway, ensure that the HTTP settings for the backend pool have the correct hostname that matches the SSL certificate.

If you are using both IP SSL and SNI bindings, avoid mixing them. Always use SNI-enabled clients to access the site, and verify that the SSL certificates bound to the IP setting encompass all necessary URLs.

Please share error screen shot for better check, if something like more detail present do post that as well here, we will check and get back to you

Thanks!

Your answer

Siva Nair 1,475 Reputation points Microsoft External Staff

2025-04-30T03:09:09.9566667+00:00

Hi Paul Olson

Please check that the SSL certificate you have configured in Azure App Service is correctly bound to your custom domain (www.olievortex.com). As you mentioned your application is defaulting to the *.azurewebsites.net certificate instead of the one linked to your custom domain.

Double-check your DNS settings. Make sure that the CNAME records for your custom domain are pointing to the correct Azure endpoint and that your TXT verification records are configured properly.

Sometimes the App Service may not sync immediately with the new certificate. You can force a sync by going to the Azure portal:

Navigate to App Service Certificates.

Select your certificate.

Click on Rekey and Sync, then choose Sync.

check that the TLS certificate installed corresponds exactly to the CNAME being used (e.g., www.olievortex.com). If there’s any inconsistency, it could lead to SSL errors.

If you are routing traffic through an Application Gateway, ensure that the HTTP settings for the backend pool have the correct hostname that matches the SSL certificate.

If you are using both IP SSL and SNI bindings, avoid mixing them. Always use SNI-enabled clients to access the site, and verify that the SSL certificates bound to the IP setting encompass all necessary URLs.

Please share error screen shot for better check, if something like more detail present do post that as well here, we will check and get back to you

Thanks!

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SSL Certificate Mismatch - Web App

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