Reflected cross-site scripting in vaadin-menu-bar webjar resources in Vaadin 14

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-2021-33611: 0.99% estimated exploitation activity in the next 30 days; percentile 62.45 (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 test sources in org.webjars.bowergithub.vaadin:vaadin-menu-bar versions 1.0.0 through 1.2.0 (Vaadin 14.0.0 through 14.4.4) allows remote attackers to execute malicious JavaScript in browser by opening crafted URL.

Published by the source

3 Nov 2021, 17:33 UTC

Last modified by the source

1 Feb 2023, 05:06 UTC

Source last checked

26 Oct 2026, 16:07 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-93c4-vf86-3rj7

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# Patch Next advisory brief: CVE-2021-33611

Advisory: Reflected cross-site scripting in vaadin-menu-bar webjar resources in Vaadin 14
IDs: CVE-2021-33611, GHSA-93c4-vf86-3rj7
Record: https://patchnext.com/advisories/cve-2021-33611 (revision 1, source checked 26 Oct 2026, 16:07 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:vaadin-bom 14.4.5; org.webjars.bowergithub.vaadin:vaadin-menu-bar 1.2.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.vaadin:vaadin-bom: affected >= 14.0.0, <= 14.4.4; fixed in 14.4.5
- Maven org.webjars.bowergithub.vaadin:vaadin-menu-bar: affected >= 1.0.0, <= 1.2.0; fixed in 1.2.1

## Suggested inspection (read-only)
- Maven com.vaadin:vaadin-bom: check the installed version with your package manager.
- Maven org.webjars.bowergithub.vaadin:vaadin-menu-bar: 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:vaadin-bom, org.webjars.bowergithub.vaadin:vaadin-menu-bar.
- 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-93c4-vf86-3rj7 (GitHub-reviewed advisory GHSA-93c4-vf86-3rj7 lists affected ranges: Maven com.vaadin:vaadin-bom >=14.0.0 =1.0.0 <=1.2.0)

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