Misskey is an open source, decentralized social media platform. In versions prior to 13.3.2 the URL preview function is subject to a cross site scripting vulnerability due to insufficient URL validation. Arbitrary JavaScript is executed when a malicious URL is loaded in the `View in Player` or `View in Window` preview. This has been fixed in version 13.3.2. Users are advised to upgrade. Users unable to upgrade should avoid usage of the `View in Player` or `View in Window` functions.