Bug 2446005 (CVE-2026-2742)

Summary:	CVE-2026-2742 com.vaadin/flow-server: Vaadin flow-server: Authentication bypass due to inconsistent path matching allows unauthorized session creation.
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	asoldano, bbaranow, bmaxwell, brian.stansberry, darran.lofthouse, dosoudil, fjuma, istudens, ivassile, iweiss, mosmerov, msvehla, nwallace, pberan, pesilva, pjindal, pmackay, rstancel, smaestri, tom.jenkinson
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in com.vaadin/flow-server. This authentication bypass vulnerability allows an unauthenticated attacker to bypass security filters by accessing the /VAADIN endpoint without a trailing slash. This inconsistent path pattern matching enables the attacker to trigger framework initialization and create sessions without proper authorization, potentially leading to unauthorized access and information disclosure.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-03-10 13:01:29 UTC

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.