Advisory by Netsparker.
Name: XSS Vulnerability in Pligg CMS
Affected Software : Pligg CMS
Affected Versions : 2.0.2 and possibly below
Vendor Homepage :
Vulnerability Type : Cross-site Scripting
Severity : Important
Status : Not fixed
Netsparker Advisory Reference : NS-15-011

Technical Details
Proof of Concept URL for XSS in Pligg CMS:

Page: groups.php
Parameter Name: keyword
Parameter Type: GET
Attack Pattern:'+alert(0x000D82)+'

For more information on cross-site scripting vulnerabilities read the article Cross-site Scripting (XSS).

Advisory Timeline
13/05/2015 - First Contact
30/06/2015 - Second Contact
16/07/2015 - Third Contact
30/07/2015 - Advisory released

Credits & Authors
These issues have been discovered by Omar Kurt while testing Netsparker Web Application Security Scanner.

About Netsparker
Netsparker finds and reports security flaws and vulnerabilities such as SQL Injection and Cross-site Scripting (XSS) in all websites and web applications regardless of the platform and the technology they are built on. Netsparker's unique detection and exploitation techniques allow it to be dead accurate in reporting vulnerabilities, hence it is the first and only False Positive Free web application security scanner.