Vulnerability in Vaadin Flow
CVE-2026-2742
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.
EPSS: 0.004 (32.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
Affected products
- Vaadin Flow — versions 1.0.0, 3.0.0, 24.0.0
- Vaadin — versions 10.0.0, 15.0.0, 24.0.0
Weakness classification (CWE)
References
- security@vaadin.com (Vendor Advisory)
- security@vaadin.com (Patch, Issue Tracking)
- security@vaadin.com (Patch, Issue Tracking)
- security@vaadin.com (Patch, Issue Tracking)
- security@vaadin.com (Patch, Issue Tracking)
- security@vaadin.com (Patch, Issue Tracking)
- security@vaadin.com (Patch, Issue Tracking)
Frequently asked questions
- What is CVE-2026-2742?
- CVE-2026-2742 is a medium-severity vulnerability in Vaadin Flow, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-03-10.
- How severe is CVE-2026-2742?
- Medium severity. CVSS v3 base score is 5.3 out of 10.