Details on the security issue are found here: http://www.crehelp.com/cre-loaded-vulnerability-check-you-are-affected-pg-7.html
We have created a patch for the NB2 store software to fix the security issue found in early February 2010.
If for some reason, you want to manually apply the code to your Niche Blueprint 2 store, you can follow the instructions here to apply the NB2 security fixes.
If you are using NB1 (the original Niche Blueprint store software), you can apply the security changes yourself here.