What’s Vulnerable › Vulnerabilities

CVE-2021-31408: Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-04-23 · updated 2026-06-17
• Weakness: CWE-613

Description

Authentication.logout() helper in com.vaadin:flow-client versions 5.0.0 prior to 6.0.0 (Vaadin 18), and 6.0.0 through 6.0.4 (Vaadin 19.0.0 through 19.0.3) uses incorrect HTTP method, which, in combination with Spring Security CSRF protection, allows local attackers to access Fusion endpoints after the user attempted to log out.

Affected products

• vaadin flow: from 5.0.0 before 6.0.0; from 6.0.0 before 6.0.5 — fixed in 6.0.0, 6.0.5
• Vaadin: from 19.0.0 before 19.0.4; 18.0.0 — fixed in 19.0.4

How to fix

Upgrade to a fixed version: vaadin flow 6.0.0, 6.0.5; Vaadin 19.0.4. Check the vendor advisory for mitigations.

References

• https://github.com/vaadin/flow/pull/10577
• https://vaadin.com/security/cve-2021-31408
• https://github.com/vaadin/flow/pull/10577
• https://vaadin.com/security/cve-2021-31408

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