CVE-2026-2742Unauthorized session creation via reserved framework path access

Description

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://vaadin.com/security/cve-2026-2742 Vendor Advisory
• https://github.com/vaadin/flow/pull/22998 Issue TrackingPatch
• https://github.com/vaadin/flow/pull/23037 Issue TrackingPatch
• https://github.com/vaadin/flow/pull/23057 Issue TrackingPatch
• https://github.com/vaadin/flow/pull/23052 Issue TrackingPatch
• https://github.com/vaadin/flow/pull/23034 Issue TrackingPatch
• https://github.com/vaadin/flow/pull/23033 Issue TrackingPatch