XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. When an admin disables a user account, the user's profile is executed with the admin's rights. This allows a user to place malicious code in the user profile before getting an admin to disable the user account. To reproduce, as a user without script nor programming rights, edit the about section of your user profile and add `{{groovy}}services.logging.getLogger("attacker").error("Hello from Groovy!"){{/groovy}}`. As an admin, go to the user profile and click the "Disable this account" button. Then, reload the page. If the logs show `attacker - Hello from Groovy!` then the instance is vulnerable. This has been patched in XWiki 14.10.21, 15.5.5, 15.10.6 and 16.0.0. Users are advised to up