There are several related questions: How can you tell what patches your server has? How do you know whether that's the latest set of patches? How do you get the latest patches? These questions are answered in the "Recommended Updates" documents.
The master Recommended Updates document for WAS is Recommended Updates for WebSphere Application Server Base and Network Deployment editions. (Reference #7004980) To get to this document, go to the main WAS page, select Support, and select Recommended Updates.
Here are some of the main update documents for different versions of WAS:
WebSphere Application Server V6.0 resources
- Update Strategy for WebSphere Application Server V6.0 release (Reference #1191989) (PDF)
- 126.96.36.199 - 6.0.1: List of Updates for Base, Network Deployment, and Express Editions (Reference #7005808)
WebSphere Application Server V5.0 and V5.1 resources
- Cumulative Fix Strategy for WebSphere Application Server V5.0 and V5.1 releases (Reference #1145289) (PDF)
- 188.8.131.52 - 184.108.40.206: List of updates for Base, Network Deployment, and Express Editions (Reference #7004936)
- 5.0.1 - 220.127.116.11: List of updates for Base, Network Deployment, and Express Editions (Reference #7004990)
WebSphere Application Server SDK (aka JDK, aka J2SE) resources
- Java SDK Upgrade policy for WebSphere Application Server (Reference #1138332)
- Verify Java SDK version shipped with WebSphere Application Server fix packs (Reference #7005002)
Previously-covered support topics: