Missing check in UIDL request handler in com.vaadin:flow-server versions 1.0.0 through 1.0.5 (Vaadin 10.0.0 through 10.0.7, and 11.0.0 through 11.0.2) allows attacker to update element property values via crafted synchronization message.
Missing output sanitization in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.10 (Vaadin 10.0.0 through 10.0.13), and 1.1.0 through 1.4.2 (Vaadin 11.0.0 through 13.0.5) allows attacker to execute malicious JavaScript via crafted URL
Cross-site scripting (XSS) vulnerability in Vaadin before 6.4.9 allows remote attackers to inject arbitrary web script or HTML via unknown vectors related to the index page.