Global Product Security

The Oracle Global Product Security Blog:
If you are looking for a place to watch security related information for Oracle products, refer the below blog:
http://blogs.oracle.com/security/

Oracle Database Security

Oracle Database Security Checklist:
This paper recaps the security checklist that can be found in newer versions of the Oracle Database Security Guide. The recommendations contained in this document are intended to be general in nature. This document provides guidance on configuring the Oracle Database based on security best practices for operational database deployments. Details on specific database-related tasks and actions can be found throughout the Oracle documentation set.
http://www.oracle.com/technology/deploy/security/database-security/pdf/twp_security_checklist_database.pdf

Critical Patch Updates

Oracle Critical Patch Updates and Security Alerts:
This page lists security patches, in the form of Critical Patch Updates (CPUs) and Security Alerts, that Oracle has released. The page is updated when new Critical Patch Updates and Security Alerts are released.
Critical Patch Updates