Reflected cross-site scripting in default RouteNotFoundError view in Vaadin 10 and 11-13

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2019-25027: 0.67% estimated exploitation activity in the next 30 days; percentile 51.96 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Missing output sanitization in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.10 (Vaadin 10.0.0 through 10.0.13), and 1.1.0 through 1.4.2 (Vaadin 11.0.0 through 13.0.5) allows attacker to execute malicious JavaScript via crafted URL. - https://vaadin.com/security/cve-2019-25027

Published by the source

19 Apr 2021, 14:52 UTC

Last modified by the source

1 Feb 2023, 05:05 UTC

Source last checked

26 Oct 2026, 16:06 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rp4x-wxqv-cf9m

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# Patch Next advisory brief: CVE-2019-25027

Advisory: Reflected cross-site scripting in default RouteNotFoundError view in Vaadin 10 and 11-13
IDs: CVE-2019-25027, GHSA-rp4x-wxqv-cf9m
Record: https://patchnext.com/advisories/cve-2019-25027 (revision 1, source checked 26 Oct 2026, 16:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: com.vaadin:flow-server 1.4.3, 1.0.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.vaadin:flow-server: affected >= 1.0.0, < 1.0.11; >= 1.1.0, < 1.4.3; fixed in 1.0.11, 1.4.3

## Suggested inspection (read-only)
- Maven com.vaadin:flow-server: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on com.vaadin:flow-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rp4x-wxqv-cf9m (GitHub-reviewed advisory GHSA-rp4x-wxqv-cf9m lists affected ranges: Maven com.vaadin:flow-server >=1.0.0 =1.1.0 <1.4.3)

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