Bob Gendler:

Since macOS 26.4, there’s been an issue with the keychain hiding in plain sight and that issue is it’ll take ANY password. Say what? The story behind CVE-2026–43728.

[…]

Where this is a bit more of a kicker…you can reset the keychain password without even knowing the real one.

[…]

Now did Apple fully fix it, well mostly. Something is different after macOS 26.4 (I believe it’s the new, User Authentication Daemon — userauthd). On macOS 26.3, if you ran security lock-keychain and then security unlock-keychain it HAD to be your keychain password. But now they added this note to the man page.

Unlocking the login keychain might succeed when an incorrect password is presented, if other unlock factors are available.

Previously:

• Locked Down Passkey and Keychain Backups
• macOS 26.6
• macOS 26.4

Bug Keychain Mac macOS Tahoe 26 securiy