Interpretation conflict in PostNuke 0.761 and earlier allows remote attackers to conduct cross-site scripting (XSS) attacks via HTML tags with a trailing "<" character, which is interpreted as a ">" character by some web browsers but bypasses the blacklist protection in (1) the pnVarCleanFromInput function in pnAPI.php, (2) the pnSecureInput function in pnAntiCracker.php, and (3) the htmltext parameter in an edituser operation to user.php.

SQL injection vulnerability in the members_list module in PostNuke 0.726, and possibly earlier, allows remote attackers to execute arbitrary SQL commands via the sortby parameter.

SQL injection vulnerability in PostNuke 7.2.6 and earlier allows remote attackers to execute arbitrary SQL via (1) the sif parameter to index.php in the Comments module or (2) timezoneoffset parameter to changeinfo.php in the Your_Account module.

Cross-site scripting (XSS) vulnerability in the Downloads module in PostNuke up to 0.726, and possibly later versions, allows remote attackers to inject arbitrary HTML and web script via the ttitle parameter in a viewdownloaddetails action.

PostNuke 0.7.2.6 allows remote attackers to gain information via a direct HTTP request to files in the (1) includes/blocks directory, (2) pnadodb directory, (3) NS-NewUser module, (4) NS-Your_Account, (5) NS-LostPassword module, or (6) NS-User module which reveals the path to the web server in a PHP error message.