URL encoding error in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows local user to execute arbitrary JavaScript code by opening crafted URL in browser.

Non-constant-time comparison of CSRF tokens in endpoint request handler in com.vaadin:flow-server versions 3.0.0 through 5.0.3 (Vaadin 15.0.0 through 18.0.6), and com.vaadin:fusion-endpoint version 6.0.0 (Vaadin 19.0.0) allows attacker to guess a security token for Fusion endpoints via timing attack.

Insecure temporary directory usage in frontend build functionality of com.vaadin:flow-server versions 2.0.9 through 2.5.2 (Vaadin 14.0.3 through Vaadin 14.5.2), 3.0 prior to 6.0 (Vaadin 15 prior to 19), and 6.0.0 through 6.0.5 (Vaadin 19.0.0 through 19.0.4) allows local users to inject malicious code into frontend resources during application rebuilds.

Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through 14.4.9), and 6.0.0 through 6.0.1 (Vaadin 19.0.0) allows attacker to access application classes and resources on the server via crafted HTTP request.

Improper sanitization of path in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.14 (Vaadin 10.0.0 through 10.0.18), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), and 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows network attacker to enumerate all available routes via crafted HTTP request when application is running in production mode and no custom handler for NotFoundException is provided.