# CVE-2026-120350: Vaadin Rich Text Editor stored XSS via video embed

Source: https://junglewise.ai/threats/cve-2026-120350-the-vaadin-rich-text-editor-exports-a-video-embed-without  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-120350 · Severity: info · Published 2026-11-10

Vaadin Rich Text Editor, a component used to build rich text editing functionality into web applications, contains a vulnerability where video embeds are not properly escaped before being parsed into the page DOM. An attacker who can edit shared content can inject malicious code into a video embed that executes in the browsers of all users who view the page, including in read-only mode, leading to account compromise or data theft.

Vendors: [Vaadin](https://junglewise.ai/threats/vendors/vaadin).

## Quick answers

**Is CVE-2026-120350 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120350 being exploited in the wild.

**How severe is CVE-2026-120350?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Vaadin Rich Text Editor 25.0.0 to 25.3.4.

**Is there a fix for CVE-2026-120350?** Yes: fixed in Vaadin 25.2.13, 25.3.5 and later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-120350 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-120350?** Check whether you run Vaadin Rich Text Editor at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Vaadin 25.2.13, 25.3.5 and later

## Technical details

The vulnerability exists in how Rich Text Editor exports video embeds via asDelta(): the href attribute value is not escaped before the HTML is parsed into live DOM, allowing attribute breakout to inject arbitrary JavaScript. The vulnerability only affects content persisted through asDelta(); the default HTML path using setValue/getValue is protected by server-side sanitization. Vaadin 24 and earlier are unaffected as they escape via browser mechanisms.

## Affected products

- Vaadin Rich Text Editor 25.0.0 to 25.3.4

## Timeline

- 2026-11-10: disclosed

## References

- [https://repo.maven.apache.org/maven2](https://repo.maven.apache.org/maven2)
- [https://registry.npmjs.org/](https://registry.npmjs.org/)