# CVE-2026-114126: Storybook WebSocket token exposure and code execution

Source: https://junglewise.ai/threats/cve-2026-114126-storybook-is-a-frontend-workshop-for-building-user-interface  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-114126 · Severity: high · CVSS 4 · Published 2026-10-21

Storybook is a frontend workshop for building UI components that developers use during development. The development server exposes a WebSocket authentication token to anyone on the local network, allowing attackers to trigger file-writing or testing functions. Combined with weak validation and the Vitest addon, an attacker can inject malicious code into story files and execute arbitrary commands with the developer's privileges.

Technologies: [storybook (npm)](https://junglewise.ai/threats/technologies/npm-storybook). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-114126 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114126 being exploited in the wild.

**How severe is CVE-2026-114126?** High severity, with a CVSS score of 4, published 21 October 2026.

**Which products and versions are affected?** @storybook/core (npm) >= 8.0.0, < 8.6.19, SEMVER:introduced=8.0.0,fixed=8.6.19; @storybook/core-server (npm) >= 8.0.0, < 8.6.19, SEMVER:introduced=8.0.0,fixed=8.6.19; @storybook/experimental-addon-test (npm) >= 8.0.0, < 8.6.19, SEMVER:introduced=8.0.0,fixed=8.6.19; storybook (npm) >= 8.0.0, < 8.6.19, SEMVER:introduced=8.0.0,fixed=8.6.19; and 3 more.

**Is there a fix for CVE-2026-114126?** Yes. @storybook/core (npm): upgrade to 8.6.19 or later; @storybook/core-server (npm): upgrade to 8.6.19 or later; @storybook/experimental-addon-test (npm): upgrade to 8.6.19 or later; storybook (npm): upgrade to 8.6.19 or later; @Storybook/Addon-Mcp: upgrade to 10.6.2 or later; @Storybook/Addon-Vitest: upgrade to 9.1.21 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114126 attacked?** It is attacked over the network or from the adjacent network, in a software library.

**Am I affected by CVE-2026-114126?** Check whether you run @storybook/core (npm), @storybook/core-server (npm), @storybook/experimental-addon-test (npm) or one of the others listed 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

- @storybook/core (npm): upgrade to 8.6.19 or later

  ```sh
  npm install @storybook/core@8.6.19
  ```

- @storybook/core-server (npm): upgrade to 8.6.19 or later

  ```sh
  npm install @storybook/core-server@8.6.19
  ```

- @storybook/experimental-addon-test (npm): upgrade to 8.6.19 or later

  ```sh
  npm install @storybook/experimental-addon-test@8.6.19
  ```

- storybook (npm): upgrade to 8.6.19 or later

  ```sh
  npm install storybook@8.6.19
  ```

- @Storybook/Addon-Mcp: upgrade to 10.6.2 or later
- @Storybook/Addon-Vitest: upgrade to 9.1.21 or later

## Technical details

The vulnerability involves WebSocket token exposure over a local network in the Storybook development server, combined with weak story file validation and potential Vitest API abuse. An unauthenticated LAN attacker can obtain the token, invoke WebSocket-backed file-writing functionality, inject code into story files, and if the Vitest addon with an old version is present, achieve code execution. The issue affects versions 8.0.0 through 8.6.18, 9.0.0 through 9.1.20, 10.0.0 through 10.6.1, and 11.0.0-alpha.0 through 11.0.0-alpha.5.

## Affected products

- Storybook Storybook 8.0.0 through 8.6.18; 9.0.0 through 9.1.20; 10.0.0 through 10.6.1; 11.0.0-alpha.0 through 11.0.0-alpha.5

## Identifiers

- CVE-2026-114126
- GHSA-px85-f4q5-jh77

## Timeline

- 2026-10-21: disclosed
- 2026-10-12: patched

## References

- [https://github.com/storybookjs/storybook/commit/243c06bf8f1e2f09446c44868ea100261e1374da](https://github.com/storybookjs/storybook/commit/243c06bf8f1e2f09446c44868ea100261e1374da)
- [https://github.com/storybookjs/storybook/commit/3be03ec6f11f4616471cebc3fc65c13e1bf8c178](https://github.com/storybookjs/storybook/commit/3be03ec6f11f4616471cebc3fc65c13e1bf8c178)

## Related threats

- [Storybook missing origin validation in preview allows code injection](https://junglewise.ai/threats/cve-2026-114125-storybook-missing-origin-validation-in-storybook-preview-allows)
- [Storybook WebSocket hijacking and RCE in development server](https://junglewise.ai/threats/cve-2026-27148-storybook-websocket-hijacking-and-rce-in-development-server)
- [Storybook environment variable exposure in build artifacts](https://junglewise.ai/threats/cve-2025-68429-storybook-environment-variable-exposure-in-build-artifacts)