Upsell advertisement information of an account can be manipulated to execute script code in the context of the users browser session. To exploit this an attacker would require temporary access to a users account or an successful social engineering attack to lure users to maliciously configured accounts. Attackers could perform malicious API requests or extract information from the users account. Please deploy the provided updates and patch releases. Sanitization of user-defined upsell content has been improved. No publicly available exploits are known.