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Vulnerability · Published Mar 10, 2026 · Assigned by Vaadin

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

Medium 5.3

In plain English

A medium-severity improper access control in flow from vaadin. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.3Medium
Exploit odds (30 days)0.4%top 61.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavencom.vaadin:flow-server14.14.1GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:flow-server23.6.7GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:flow-server24.9.8GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:flow-server25.0.2GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:vaadin25.0.2GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:vaadin24.9.8GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:vaadin23.6.7GHSA-rjgh-wgc7-m37j
Mavencom.vaadin:vaadin14.14.1GHSA-rjgh-wgc7-m37j

Affected products (as reported)

VendorProductVersions
vaadin vaadin 10.0.0 – through 14.14.015.0.0 – through 23.6.624.0.0 – through 24.9.725.0.0 – through 25.0.1
vaadin flow 1.0.0 – through 2.13.03.0.0 – through 23.6.724.0.0 – through 24.9.725.0.0 – before 25.0.1

Weakness: CWE-284 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/S:N/AU:Y/R:A/V:D/RE:L/U:Amber

References