Flex SDK version 3.4, the latest production quality release, has been released. You can download it from the Flex Open Source page. We are not releasing a new version of Flex Builder. However, the SDK 3.4 version will work in Flex Builder using the multi-sdk feature. You may want to postpone updating if you’re using the Data Visualization components, they will be available in about a week when SDK 3.4 is posted on the Adobe.com site.
This release supports the security updated runtimes for Flash Player 10 and AIR 1.5. Additionally, it includes key bug fixes in the SDK, one of which addresses a critical security bug (more below), and bug fixes provided by the community.
An important vulnerability has been identified in Flex SDK 3.3 and earlier versions. This vulnerability could result in cross-site scripting. We recommend all users of Flex SDK 3.3 and earlier versions update to the newest version, Flex SDK 3.4. Please refer to this security bulletin for further information.
You can find the SDK bugs that were fixed in Flex SDK 3.4 here.