GHSA-fr26-qjc8-mvjx — flow-server
MEDIUMGHSA-fr26-qjc8-mvjx is a medium-severity (CVSS 5.3) vulnerability in com.vaadin:flow-server. A fix is available for com.vaadin:flow-server — see the affected versions and patch details below.
Possible route enumeration in production mode via RouteNotFoundError view in Vaadin 10, 11-14, and 15-19
Real-World Exposure
com.vaadin:flow-server☕com.vaadin:flow-server☕com.vaadin:flow-serverReal-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
Improper sanitization of path in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.14 (Vaadin 10.0.0 through 10.0.18), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), and 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows network attacker to enumerate all available routes via crafted HTTP request when application is running in production mode and no custom handler for NotFoundException is provided.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.vaadin:flow-server | ≥ 1.0.0&&< 1.0.15 | 1.0.15com.vaadin:flow-server:1.0.15 |
| ☕Maven | com.vaadin:flow-server | ≥ 1.1.0&&< 2.6.2 | 2.6.2com.vaadin:flow-server:2.6.2 |
| ☕Maven | com.vaadin:flow-server | ≥ 3.0.0&&< 6.0.10 | 6.0.10com.vaadin:flow-server:6.0.10 |
Detection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update com.vaadin:flow-server to 1.0.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fr26-qjc8-mvjx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-fr26-qjc8-mvjx can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fr26-qjc8-mvjx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fr26-qjc8-mvjx in your dependencies?
O3 Security finds GHSA-fr26-qjc8-mvjx across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.