Comment by elmigranto

It is, but OS X won't accept it and will not unlock Keychain item, unless all the apps that do this are in Accessibility. So if there is an app that uses those APIs but not in Accessibility, even you yourself won't be able to copy anything password-protected from Keychain.

https://support.apple.com/en-us/HT205375

  SecurityAgent
  Available for: OS X El Capitan 10.11

  Impact: A malicious application can programmatically control keychain access prompts

  Description: A method existed for applications to create synthetic clicks on keychain prompts. This was addressed by disabling synthetic clicks for keychain access windows.

  CVE-ID
  CVE-2015-5943