CVE-2021-31403: Vaadin

Low severity, CVSS 2.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:vaadin-server versions 7.0.0 through 7.7.23 (Vaadin 7.0.0 through 7.7.23), and 8.0.0 through 8.12.2 (Vaadin 8.0.0 through 8.12.2) allows attacker to guess a security token via timing attack

Affected products

• Vaadin Vaadin: from 7.0.0, before 7.7.24 (fixed in 7.7.24); from 8.0.0, before 8.12.3 (fixed in 8.12.3)

Published 2021-04-23. Last modified 2026-06-17.