CVE-2021-31412: Vaadin Flow

Medium severity, CVSS 5.3. EPSS: 1.3% chance of exploitation in the next 30 days.

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.

Affected products

• Vaadin Flow: from 1.0.0, up to and including 1.0.14; from 1.1.0, up to and including 1.4.0; from 2.0.0, up to and including 2.6.1; from 3.0.0, up to and including 5.0.0; from 6.0.0, up to and including 6.0.9
• Vaadin Vaadin: from 10.0.0, up to and including 10.0.18; from 11.0.0, up to and including 13.0.0; from 14.0.0, up to and including 14.6.1; from 15.0.0, up to and including 18.0.0; from 19.0.0, up to and including 19.0.8

Published 2021-06-24. Last modified 2026-06-17.