This post will cover both the question and answer for the Siteground Cloudflare SSL Pending Validation topic.
Question: I have Siteground hosting and integrated Cloudflare. Why is my Cloudflare, SSL/TLS, Edge Certificates stuck in a pending validation state?
Answer: At least for me, is because Siteground does not add the Universal Certificate Validation Files after integrating your website. They do add the proper DNS records, but they do not add the necessary text files in your SITEGROUND WEBSITE DASHBOARD > SITE > FILE MANAGER.
How can you fix this?
Navigate to your Cloudflare Dashboard > SSL/TLS > Edge Certificates
Under your Edge Certificates, it will list two variations of your domain.
If you click on each one, it will list a request address and a response (for this request)
Note: Essentially, Cloudflare is making the above request, and they are expecting the given response.
You need to create these directories and text files (with expected response) in your Siteground Dashboard > File Manager
So, lets say the Cloudflare requested URL is “http://yoursite.com/subdirectory1/subdirectory2/randomstring.txt”
In your Siteground Dashboard > File Manager
You create the following directories and files within the public_html directory
public_html > subdirectory1 > subdirectory2 > randomstring.txt (this has the response they are expecting)
You create a file for each version of your domain.
If you’re still unsure about the directories for whatever reason. Check your Siteground Dashboard > Statistics > Error Log
This will display a list of attempts Cloudflare has made to resolve the Edge Certificate and in what directory your server is looking for the files. It seems to make an attempt every ~20 minutes or so. After creating the above files, wait ~20 minutes for your Edge Certificates to resolve. If they haven’t resolved within the given time. You most likely have a different issue. The above answer fixed my issue. Hope this helps.