Apple released security updates for Snow Leopard (OS X 10.6) and Lion (OS X 10.7) on Tuesday, for both the client and server versions of the OSes.
The patch notes for all four updates say precisely nothing, and Apple's security update page—where security patch notes get released—has not yet been updated with these releases. Accordingly, we don't yet know what was patched in these updates.
OS X 10.6 (Snow Leopard) and OS X 10.7 (Lion)
- About Security Update 2013-002 (Lion) - 57.68MB
- About Security Update 2013-002 Server (Lion) - 105.61MB
- About Security Update 2013-002 (Snow Leopard) - 329.85MB
- About Security Update 2013-002 Server (Snow Leopard) - 404.83MB
If yo are running the specific OSes, you'll also find the updates in Software Update on your Mac.