CVE-2026-2742: Vaadin

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

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 you should update either to the latest 14, 23, 24, 25 version.

Affected products

• Vaadin Vaadin: from 10.0.0, before 14.14.1 (fixed in 14.14.1); from 15.0.0, before 23.6.7 (fixed in 23.6.7); from 24.0.0, before 24.9.8 (fixed in 24.9.8); from 25.0.0, before 25.0.2 (fixed in 25.0.2)

Published 2026-03-10. Last modified 2026-06-17.