An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved framework paths.
Accessing the /VAADIN endpoint without a trailing slash bypasses security filters, and allowing unauthenticated users to trigger framework initialization and create sessions without proper authorization.
Users of affected versions using Spring Security should upgrade as follows: 14.0.0-14.14.0 upgrade to 14.14.1, 23.0.0-23.6.6 to 23.6.7, 24.0.0 - 24.9.7 to 24.9.8, and 25.0.0-25.0.1 upgrade to 25.0.2 or newer.
Please note that Vaadin versions 10-13 and 15-22 are no longer supported and users should update either to the latest 14, 23, 24, 25 version.
Action captions in Vaadin accept HTML by default but were not sanitized, potentially allowing Cross-site Scripting (XSS) if caption content is derived from user input.
In Vaadin Framework 7 and 8, the Action class is a general-purpose class that may be used by multiple components. The fixed versions sanitize captions by default and provide an API to explicitly enable HTML content mode for backwards compatibility.
In Vaadin 23 and newer, the Action class is only used by the Spreadsheet component. The fixed versions sanitize HTML using Jsoup with a relaxed safelist.
Vaadin 14 is not affected as Spreadsheet component was not supported.
Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include:
Product version Vaadin 7.0.0 - 7.7.49 Vaadin 8.0.0 - 8.29.1 Vaadin 23.1.0 - 23.6.5 Vaadin 24.0.0 - 24.8.13 Vaadin 24.9.0 - 24.9.6
Mitigation Upgrade to 7.7.50 Upgrade to 8.30.0 Upgrade to 23.6.6 Upgrade to 24.8.14 or 24.9.7 Upgrade to 25.0.0 or newer
Artifacts Maven coordinatesVulnerable versionsFixed versioncom.vaadin:vaadin-server 7.0.0 - 7.7.49 ≥7.7.50 com.vaadin:vaadin-server 8.0.0 - 8.29.1 ≥8.30.0 com.vaadin:vaadin 23.1.0 - 23.6.5 ≥23.6.6 com.vaadin:vaadin24.0.0 - 24.8.13 ≥24.8.14 com.vaadin:vaadin24.9.0 - 24.9.6 ≥24.9.7 com.vaadin:vaadin-spreadsheet-flow 23.1.0 - 23.6.5 ≥23.6.6 com.vaadin:vaadin-spreadsheet-flow 24.0.0 - 24.8.13 ≥24.8.14 com.vaadin:vaadin-spreadsheet-flow 24.9.0 - 24.9.6 ≥24.9.7