Skip to content
Noroxi
CVE.org (no NVD analysis yet)· CNA Vaadin

CVE-2026-120350: Stored Cross-Site Scripting in the Vaadin Rich Text Editor via an Unescaped Video Embed

MediumCVSS 5.1 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 20/100)

  • 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: 0.26% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No special conditions are required; it is repeatable.
  • Fixed version: vaadin rich-text-editor 25.2.17, 25.3.5; vaadin vaadin 25.2.13, 25.3.5; vaadin vaadin-core 25.2.13, 25.3.5.

Low priority for now. Upgrade to vaadin rich-text-editor 25.2.17, 25.3.5; vaadin vaadin 25.2.13, 25.3.5; vaadin vaadin-core 25.2.13, 25.3.5 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

The Vaadin Rich Text Editor exports a video embed without escaping its value, and then parses the resulting HTML into live DOM. A value crafted to break out of the href attribute therefore runs script in the viewer's browser. An attacker who can edit shared content pastes a video embed carrying the payload, the delta is stored, and the script runs when any user opens the page, including in read only mode. Only content persisted through asDelta() is affected. The default HTML value, set and read through setValue and getValue, is sanitized on the server with a safelist that has no iframe, so the embed does not survive that path. Vaadin 24 and older are not affected: they build the HTML value from the editor's own innerHTML, which the browser escapes. Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include: Product version Vaadin 25.0.0 - 25.0.13 Vaadin 25.1.0 - 25.1.13 Vaadin 25.2.0 - 25.2.12 Vaadin 25.3.0 - 25.3.4 Mitigation No fixed release on this line, upgrade to 25.2.13 or newer No fixed release on this line, upgrade to 25.2.13 or newer Upgrade to 25.2.13 Upgrade to 25.3.5

Published
Nov 10, 2026
Updated
Nov 10, 2026
EPSS
0.2% · 19th percentile

Report tools

JSON

Action score

20

Monitor

Low priority for now.

CVSS
20 / 40 · 5.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CNA vs NVD score

NVD
—
CNA · Vaadin
5.1
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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.

Follow CVE-2026-120350

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Is the Quill on your site affected?Scan JavaScript libraries

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for vaadin records

Is the Quill on your site affected?Scan JavaScript libraries

Is your version affected? Check it

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.

We use this product, ask for help

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.

—

Is the Quill on your site affected?

The free JavaScript library scanner reads the Quill version from the files your site loads, matches this record and other known vulnerabilities, and gives the safe version on the same branch. If the version can't be read, it says so. No account needed.

Scan JavaScript libraries

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 rich-text-editor

    • 25.0.0 and later · up to and including 25.0.13affected · semver
    • 25.1.0 and later · up to and including 25.1.14affected · semver
    • 25.2.0 and later · before 25.2.17affected · semver
    • 25.3.0 and later · before 25.3.5affected · semver

  • vaadin vaadin

    • 25.0.0 and later · up to and including 25.0.13affected · maven
    • 25.1.0 and later · up to and including 25.1.13affected · maven
    • 25.2.0 and later · before 25.2.13affected · maven
    • 25.3.0 and later · before 25.3.5affected · maven

  • vaadin vaadin-core

    • 25.0.0 and later · up to and including 25.0.13affected · maven
    • 25.1.0 and later · up to and including 25.1.13affected · maven
    • 25.2.0 and later · before 25.2.13affected · maven
    • 25.3.0 and later · before 25.3.5affected · maven

  • vaadin vaadin-rich-text-editor-flow

    • 25.0.0 and later · up to and including 25.0.13affected · maven
    • 25.1.0 and later · up to and including 25.1.13affected · maven
    • 25.2.0 and later · before 25.2.13affected · maven
    • 25.3.0 and later · before 25.3.5affected · maven

Package-level exposure

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

EcosystemPackageAffected rangeFix
npmquillfrom 2.0.3 · up to and including 2.0.3—

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-2026-93547Sep 30, 2026 · Missing Authorization Check in Vaadin Spreadsheet Allows Cell Comments to Be Written to Protected Sheets and Locked Cells
    21Monitor
  • ← EarlierCVE-2026-110737Oct 27, 2026 · Push Endpoint Returns Permissive CORS Headers
    9Monitor
  • ← EarlierCVE-2026-120326Nov 10, 2026 · Unescaped Download File Name Allows Content-Disposition Parameter Injection in Vaadin Flow
    19Monitor

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
vaadin rich-text-editor25.2.17Vendor (CNA)
vaadin rich-text-editor25.3.5Vendor (CNA)
vaadin vaadin25.2.13Vendor (CNA)
vaadin vaadin25.3.5Vendor (CNA)
vaadin vaadin-core25.2.13Vendor (CNA)
vaadin vaadin-core25.3.5Vendor (CNA)
vaadin vaadin-rich-text-editor-flow25.2.13Vendor (CNA)
vaadin vaadin-rich-text-editor-flow25.3.5Vendor (CNA)

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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+3 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-10758820 days apartMultiple Vulnerabilities in the Highcharts Library Bundled with Vaadin Charts
    33Monitor
  • CVE-2025-15022309 days apartCross-site scripting in Action caption
    19Monitor

Not on record for this CVE: researcher credit · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
P
Scope
X

Weakness class (CWE)

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

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

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

Show all references (2 more)

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

All records