Apple has disabled the Java 7 plugin on Macs through its OS X anti-malware system, in order to protect users from a potentially serious security issue.
From Apple Insider:
The newly discovered zero-day flaw in Java 7 is so serious that the U.S. Department of Homeland Security has warned users to disable or uninstall it.Zero-day flaw prompts Apple to block Java 7 from OS X
"We are currently unaware of a practical solution to this problem," the departments' Computer Emergency Readiness Team said. "This vulnerability is being attacked in the wild, and is reported to be incorporated into exploit kits. Exploit code for this vulnerability is also available."
