Several sites provide easy ways to get CVSS scores. Several of the major ones are listed below.
NIST NVD site has all alerts CVSS scored and presented at the below URL
http://nvd.nist.gov/nvd.cfm
They also have XML feeds that anyone can use
http://nvd.nist.gov/download.cfm#XML
ISS and X-force CVSS score all of their alerts
http://xforce.iss.net/xforce/alerts
Qualys
http://www.qualys.com/research/alerts/
Cisco
http://www.cisco.com/security
A link to Tenable's vulnerability checks is :
http://www.nessus.org/plugins/
Browsing a plugin reveals a CVSS score when available; eg,
http://www.nessus.org/plugins/index.php?view=single&id=23649
Security Database
http://www.security-database.com/cvss.php
NVD calculator
http://nvd.nist.gov/cvss.cfm?calculator
Patch Advisor
http://www.patchadvisor.com/PatchAdvisor/CVSSCalculator.aspx
Information-Technology Promotion Agency, Japan
http://jvnrss.ise.chuo-u.ac.jp/jtg/cvss/en/index.01.html
Cisco
http://intellishield.cisco.com/security/alertmanager/cvss
Goebel Consult
http://www.goebel-consult.de/cvss/
Bricade CVSS V2.0 Calculator
https://www.bricade.com/calc3.asp
