Trying to Validate domain ownership in ACM , stuck at pending after CNAM created

HI, Good question

Please note you need to validate

Before ACM issues a certificate, it validates that you own or control the domain names in your certificate request. You can use either email validation or DNS validation.

If you choose email validation, ACM sends validation email to three contact addresses registered in the WHOIS database, and to five common system administration addresses for each domain name. You or an authorized representative must reply to one of these email messages. For more information, see Email validation.

If you use DNS validation, you simply add a CNAME record provided by ACM to your DNS configuration. For more information about DNS validation, see DNS validation.

More info at https://docs.aws.amazon.com/acm/latest/userguide/gs-acm-request-public.html

Email Validation: https://docs.aws.amazon.com/acm/latest/userguide/email-validation.html

DNS validation: https://docs.aws.amazon.com/acm/latest/userguide/dns-validation.html

How did you add the CNAME record in Route53 - was it manually or through ACM? If it's manually, check if the domain is not repeated at the end of the Record name.

I suggest to use the "Create record in Route 53" button in ACM, if this was not yet done.

More information about ACM DNS validation can be found here: https://docs.aws.amazon.com/acm/latest/userguide/dns-validation.html