The new update comes roughly six weeks after the release of Safari 7.0.3, which included a more substantial list of improvements. Safari 7.0.3 was later bundled into OS X 10.9.3, which was released last week.The Safari 7.0.4 update is recommended for all OS X Mavericks users and contains improvements to security.
For detailed information on the security content of this update, please visit:
http://support.apple.com/kb/HT1222
Safari 7.0.4 and 6.1.4 are free downloads available through the Software Update mechanism in the Mac App Store.
Article Link: Apple Releases Safari 7.0.4 and 6.1.4 with Security Fixes