It is normally not enough to just install the FMW software you will also need to apply different kind of patches.

Security patches

Each quarter Oracle releases security updates. The patch program is called the Critical Patch Update (CPU).

In the beginning the patches released by the CPU program was also called CPU patches. From October 2012 the name was changed to Security Patch Update (SPU). The program is still called CPU but the patches are called SPU patches.

A SPU patch is a cumulative patch consisting of security fixes.

For some products the SPU patches has been replaced with Patch Set Updates (PSU). This is true for the database and the WebLogic server. You can see the full product list in “Patch Set Updates for Oracle Products (Doc ID 854428.1)”.

For WebLogic server 10.3.4 and newer only PSU patches are released!

A PSU patch is a cumulative patch consisting of security fixes and other stabilizing patches. Basically it is a SPU plus extra not security related patches.

Since SPU/PSU patches are cumulative they will conflict with each other, so you will need to remove older SPU/PSU patch before applying a new one.

A version number is associated with a PSU patch. The fifth number of the version is incremented for each PSU.

Here is a WebLogic server 10.3.6 with the July PSU.

. /u01/app/oracle/product/wls103/wlserver_10.3/server/bin/setWLSEnv.sh
java weblogic.version

WebLogic Server 10.3.6.0.5 PSU Patch for BUG16619891 Tue Apr 23 13:24:29 IST 2013
WebLogic Server 10.3.6.0  Tue Nov 15 08:52:36 PST 2011 1441050

Sometimes you need to install one-off patches that are not included in the PSU. They can conflict with PSU patchs and therefore you will sometimes see a one-off patch that exists in several versions. The one-off patch must match the version number of the PSU.

At the moment there are 4 required one-off WebLogic patches you must apply when installing the OSB 11.1.1.7.

One of them conflict with the PSU and you must install an overlay patch that matches the PSU version number.

The 13573621 patch has 5 overlay patches.

Every time the CPU program releases patches you should check for new WebLogic PSU patches and for SPU patches for the FMW products you have installed on top of WebLogic – OSB, SOA Suite etc.

You can see the release schedule here.

Make sure you sign up for email notifications.

If a serious bug is found Oracle might immediately release an one-off security patch. If you sign up for email notifications you will get an mail when this happens.

Normally the patch will also be included in the next SPU/PSU.

Bundle Patches

Sometimes Oracle will find bugs or important enhancements between releases of a product. If the changes are important enough a Bundle Patch (BP) will be released.

BPs are released on the same quarterly schedule as the CPU program and they are cumulative just like the SPU/PSU’s.

As an example the SOA Suite 11.1.1.6 currently have 6 BPs.

I don’t know of any way to be notified about new BPs.

You can find a list of all BPs here:
“Master Note on Fusion Middleware Proactive Patching – Patch Set Updates (PSUs) and Bundle Patches (BPs) (Doc ID 1494151.1)”

I might be an idea to follow Mustafa Kaya’s blog.

Suite Bundle Patches

A Suite Bundle Patch is a collection of product Bundle Patches for a suite (e.g., an Oracle Identity Management Suite bundle patch consisting of OAM, OAAM, and OIM).

I do not have experience with those.

Additional information

It might also be worth keeping an eye on this new Information Center:
“Weblogic Server Patching & Maintenance Information Center (Doc ID 1573509.2)”