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GHSA-rjgh-wgc7-m37j — flow-server

Fix: vaadin/flow#22998

GHSA-rjgh-wgc7-m37j is a CWE-284 vulnerability in com.vaadin:flow-server. A fix is available for com.vaadin:flow-server — see the affected versions and patch details below.

Vaadin Vulnerable to Authentication Bypass When Accessing the /VAADIN Endpoint Without a Trailing Slash

Also known asCVE-2026-2742
Published
Mar 10, 2026
Updated
Sep 10, 2026
Affected
8 pkgs
Patched
8 / 8
Exploits
None indexed
Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-rjgh-wgc7-m37j.

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs37th percentile — riskier than 37% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

8 pkgs affected
☕com.vaadin:flow-server☕com.vaadin:flow-server☕com.vaadin:flow-server☕com.vaadin:flow-server☕com.vaadin:vaadin☕com.vaadin:vaadin☕com.vaadin:vaadin☕com.vaadin:vaadin

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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 users should update either to the latest 14, 23, 24, 25 version.

Affected Packages

8 total 8 fixed
EcosystemPackageVulnerable rangeFix
☕Mavencom.vaadin:flow-serverall versions14.14.1com.vaadin:flow-server:14.14.1
☕Mavencom.vaadin:flow-server≥ 23.0.0&&< 23.6.723.6.7com.vaadin:flow-server:23.6.7
☕Mavencom.vaadin:flow-server≥ 24.0.0&&< 24.9.824.9.8com.vaadin:flow-server:24.9.8
☕Mavencom.vaadin:flow-server≥ 25.0.0&&< 25.0.225.0.2com.vaadin:flow-server:25.0.2
☕Mavencom.vaadin:vaadin≥ 25.0.0&&< 25.0.225.0.2com.vaadin:vaadin:25.0.2
☕Mavencom.vaadin:vaadin≥ 24.0.0&&< 24.9.824.9.8com.vaadin:vaadin:24.9.8

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.vaadin:flow-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update com.vaadin:flow-server to 14.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rjgh-wgc7-m37j is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-rjgh-wgc7-m37j can be triaged on real exposure rather than presence alone.

Tailored to GHSA-rjgh-wgc7-m37j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate
Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for GHSA-rjgh-wgc7-m37j (CC BY 4.0)

Frequently Asked Questions

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, 
O3 Security · Impact-Aware SCA

Is GHSA-rjgh-wgc7-m37j in your dependencies?

O3 Security finds GHSA-rjgh-wgc7-m37j across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

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