Glossary
Credential Autofill
Credential autofill is a password manager automatically inserting a stored username and password into a login form it determines belongs to the site the credential was originally saved for. The convenience is real: it removes the temptation to reuse a memorable password across sites, since the manager remembers a unique one for each. The safety of the convenience depends entirely on how accurately the manager determines that the current page is genuinely the site the credential belongs to, rather than a convincing lookalike.
A password manager that matches loosely — by visual similarity or a partial domain match rather than the exact, verified origin — can be tricked into autofilling credentials onto a phishing page that merely looks similar to the real site. This is exactly the same origin-verification discipline that makes passkeys structurally phishing-resistant, applied here to a different mechanism with a real, if narrower, version of the same protection when the matching is done strictly.