MakeSecure.com is designed to facilitate discussion on security related topics, create network security awareness, and provide secure solutions.

Vulnerability and patch alerts [RSS]

SecurityFocus is designed to facilitate discussion on computer security related topics, create computer security awareness, and to provide the Internet's largest and most comprehensive database of computer security knowledge and resources to the public. It also hosts the BUGTRAQ mailing list.

SANS Internet Storm Center - A global cooperative cyber threat / internet security monitor and alert system. Featuring daily handler diaries with summarizing and analyzing new threats to networks and internet security events.

Software vendor for patch management of operating systems and applications.

eVuln.com - Penetration Tests & Security Advisories List

Fee based security alert service that provides early warning of active attacks.

Fee based patch alert service.

AusCERT - Australia's National CERT

Established in 2003 to protect the nation's Internet infrastructure, US-CERT coordinates defense against and responses to cyber attacks across the nation.