source: https://www.securityfocus.com/bid/19718/info

MyBB is prone to multiple HTML-injection vulnerabilities because it fails to properly sanitize user-supplied input before using it in dynamically generated content. 

Attacker-supplied HTML and script code would execute in the context of the affected website, potentially allowing an attacker to steal cookie-based authentication credentials or to control how the site is rendered to the user; other attacks are also possible.

Version 1.1.7 is vulnerable; other versions may be affected.

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