However it seems that according to a report from The Information (paywall; via Engadget), there might be a security bug that could have potentially exposed users’ passwords. Apparently what happened is that when some users use the feature, the password to their accounts was sent in plaintext in the URL, which is a huge problem since hackers might be able to pick up on that.
However the good news is that according to Instagram, they told The Information that this flaw only impacted a small number of people, although this could still be a problem if those users used a shared computer in which the person using the computer after them could potentially retrieve said information.
If you did not receive any notification or message from Instagram, then it means that your account should be safe. However if you’d rather not take that risk, perhaps updating your passwords or enabling two-factor authentication might not be such a bad idea.