If I administer a webpage that allows users to create accounts and log in, and assuming I am not a complete idiot so I don't keep or even ever have access to any plaintext passwords, is it possible for me to detect that one of my users is using a known bad password?

I am guessing that if I also salt my password hashes, which I do, this means there is no way of detecting any compromised passwords from among the ones already in use by my users. Sure, I could use the have I been pwned lists to check passwords before hashing and salting when a new user creates an account, but I can't think of a way of checking my existing user' passwords.

Am I missing something? I am not a security expert in any way, shape or form. Is there some way to go through a properly stored DB of hashed and salted passwords to check for known compromised passwords?

If I administer a webpage that allows users to create accounts, and assuming I don't keep or even ever have access to plaintext passwords, is it possible for me to detect that one of my users is using a known bad password?

I am guessing that if I salt my password hashes, which I do, this means there is no way of detecting any compromised passwords from among the ones already in use by my users. Sure, I could use the have I been pwned lists to check passwords before hashing and salting when a user creates a password, but I can't think of a way of checking salted hashes.

Am I missing something? Is there some way to go through a properly stored DB of salted hashes to check for known compromised passwords?