MISP contains a stored cross-site scripting (XSS) vulnerability in the admin email composition screen. The MISP.org organization name setting was interpolated directly into a JavaScript string literal using an unescaped PHP echo: var org = "";. Because the value was placed inside a double-quoted JavaScript string without any encoding, an organization name containing a double-quote character (or a backslash) could terminate the string literal and inject arbitrary JavaScript into the page. The injected script would execute in the context of any authenticated user who subsequently loads the admin email page, potentially allowing session hijacking, data exfiltration, or privileged actions performed on behalf of the victim.
Exploitation requires the ability to set or modify the MISP.org organization name and a second authenticated user visiting the affected admin email view.
The vulnerability is a classic instance of insufficient output encoding in a JavaScript context.