Rails 3.2.2 has been released. This release contains various bug fixes and two important security fixes. All users are recommended to upgrade as soon as possible.
For information regarding the possible vulnerabilities, please see the announcements here and here.
Some highlights from this release are:
Log files are always flushed
Failing tests will exit with nonzero status code
Elimination of calls to deprecated methods
Query cache instrumentation includes bindings in the payload
Hidden checkbox values are not set if the value is nil
Various Ruby 2.0 compatibility fixes
For a comprehensive list, see the commits on github.