Apple's Passwords app in iOS 18 warns users when saved credentials appear in data leaks. These alerts don't necessarily mean your account was hacked, but flag passwords that could be misused. iOS compares stored passwords against a local list of commonly leaked credentials. For others, privacy-preserving cryptographic checks with Apple's servers are used, sending derived information rather than the password itself.
Flagged accounts are stored in the Passwords app for review. Users can view compromised, reused, or weak passwords by tapping Security in the Passwords app. To fix a leaked password, users must change it on the website first, then update saved credentials.
Reused passwords should be changed everywhere, especially for email and banking. Consider using passkeys and enabling two-factor authentication for added security. Monitoring can be checked in Settings under Apps > Passwords > Detect Compromised Passwords.
Source: Engadget · Summarized by HeadlinesBriefing