The Mac maker released the update, version 10.5.4, yesterday. It urged users running earlier versions of Leopard to upgrade.
The update fixes 25 security vulnerabilities, addressing Alias Manager, Core Types, c++filt, Dock, Launch Services, Net-SNMP, Ruby, SMB file server, system configuration, Tomcat, virtual private networking and WebKit.
In terms of performance issues, the update improves L2TP client reliability and the way the AirPort hardware works with 5GHz wireless networks, Apple said in the update support document.
With regards to the Safari browser, the update addresses a potential performance issue when the user loads secure web pages and also issues that could be encountered when accessing secure web pages with client certificates that reside on a smartcard.
The update is available from Apple's website and through the operating system's Software Update control panel.