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NVD / CVE Program· CNA Vaadin

CVE-2021-33611: Reflected cross-site scripting in vaadin-menu-bar webjar resources in Vaadin 14

MediumCVSS 6.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 24/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.98% (FIRST EPSS); higher than 62.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: com.vaadin:vaadin-bom (Maven) 14.4.5; org.webjars.bowergithub.vaadin:vaadin-menu-bar (Maven) 1.2.1.

Low priority for now. Upgrade to com.vaadin:vaadin-bom (Maven) 14.4.5; org.webjars.bowergithub.vaadin:vaadin-menu-bar (Maven) 1.2.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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
Nov 2, 2021
Updated
Jun 16, 2026
EPSS
0.9% · 62th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

CNA vs NVD score

NVD
6.1
CNA · Vaadin
6.1
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
vaadinvaadin
vaadinvaadin-menu-bar

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Vaadin). Independent of NVD's CPE analysis and usually ahead of it.

  • Vaadin Vaadin

    • 14.0.0 and later · before unspecifiedaffected
    • unspecified and later · up to and including 14.4.4affected

  • Vaadin vaadin-menu-bar

    • 1.0.0 and later · before unspecifiedaffected
    • unspecified and later · up to and including 1.2.0affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • vaadin vaadin14.0.0 and later · up to 14.4.4 inclusive
  • vaadin vaadin-menu-bar1.0.0 and later · up to 1.2.0 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Mavencom.vaadin:vaadin-bomfrom 14.0.0 · before 14.4.514.4.5
Mavenorg.webjars.bowergithub.vaadin:vaadin-menu-barfrom 1.0.0 · before 1.2.11.2.1

Same product

vaadin: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-107588Multiple Vulnerabilities in the Highcharts Library Bundled with Vaadin Charts
    33Monitor
  • CVE-2021-31409Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19
    31Monitor
  • CVE-2020-36320Regular expression Denial of Service (ReDoS) in EmailValidator class in Vaadin 7
    31Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-31403Apr 23, 2021 · Timing side channel vulnerability in UIDL request handler in Vaadin 7 and 8
    10Monitor
  • ← EarlierCVE-2021-33609Oct 13, 2021 · Denial of service in DataCommunicator class in Vaadin 8
    17Monitor
  • Later →CVE-2022-29567May 24, 2022 · Possible information disclosure inside TreeGrid component with default data provider
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Maven:com.vaadin:vaadin-bom14.4.5Package registry (OSV)
Maven:org.webjars.bowergithub.vaadin:vaadin-menu-bar1.2.1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

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

nvd-primary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records