After you upgrade CQ5.5 instance to the latest Service Pack 2, consider installing these recommended hot fixes.
- NPR-2582 - References on moved pages not updated upon a page move
- NPR-2555 - First deployment of system bundle fragment leads to shutdown of Felix
- NPR-2661 - DAM doesn't search content from MS x documents (pptx, docx, xlsx)
- NPR-2774 - Missing vanity URL validation breaks whole Sling Resource Resolver
- NPR-2842 - XSS issues in the ootb foundation components
- NPR-2474 - high memory usage during large replication
- NPR-2420 - replication performance improvements
- NPR-3659 - Security hotfix (publicly available)
You can find all the above mentioned hot fixes from the Package Share's Public Section. You can access the Package Share with a registered user as mentioned here.