Misskey is an open source, federated social media platform. From 12.0.0 until 2026.7.0, the RSS components display feed item links from configured feeds without verifying their URL schemes. Missing URL scheme verification allows an attacker who controls feed content to provide an unsafe-scheme link that causes script execution when a user clicks it in an RSS widget. This issue is fixed in version 2026.7.0.
Improper Neutralization of Input During Web Page Generation The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.