Corrupted keychain usernames and passwords

So today while logging to a site with Safari I've noticed strange auto password fill suggestions which looked something like MDIEEPgAAAAAAA.......cEdj7mcA==

At first I ignored it, but then I saw it again, another login form. I went to the keychain access and surprise, I have a ton of these

These are just a few, I have many more.

All those entries are from 27.07.2017 ~16:30h

They look like base64 encoded text but when I decode it looks like binary data.

Then I've checked the installed updates, turns out a a few minutes later 2 updates completed.

What are the odds those updates broke my login entries and does anyone know how can I fix them?

Any help will be greatly appreciated 😉

regards