CVE-2026-114126

High

Description

Storybook is a frontend workshop for building user interface components and pages in isolation. From 8.0.0 until 8.6.19, 9.1.21, 10.6.2, and 11.0.0-alpha.6, the Storybook development server can expose its WebSocket authentication token to clients able to load its HTML pages over a local network. A LAN attacker can obtain the token and invoke WebSocket-backed file-writing or testing functionality. Weak story-write validation can allow code to be placed in story files. If the Storybook Vitest addon is installed with an old version of Vitest, the payload can use a Vitest API to write additional files or execute commands. Depending on the payload and local tooling, the attack can lead to code execution with the developer's privileges. This issue is fixed in 8.6.19, 9.1.21, 10.6.2, and 11.0.0-alpha.6.

SeverityHigh
CVSS8.7
Exploit probability—
ProductStorybook
PublishedOct 21, 2026
First seenOct 21, 2026

How to fix

Update
  • storybook8.6.19, 9.1.21, 10.6.2, 11.0.0-alpha.6 or later
  • @storybook/core8.6.19 or later
  • @storybook/core-server8.6.19 or later
  • @storybook/experimental-addon-test8.6.19 or later
  • @storybook/addon-vitest9.1.21, 10.6.2, 11.0.0-alpha.6 or later
  • @storybook/addon-mcp10.6.2, 11.0.0-alpha.6 or later

Affected products

ProductAffected versionsFixed in
storybooknpm8.0.0 ≤ v < 8.6.19, 9.0.0 ≤ v < 9.1.21, 10.0.0 ≤ v < 10.6.2, 11.0.0-alpha.0 ≤ v < 11.0.0-alpha.68.6.19, 9.1.21, 10.6.2, 11.0.0-alpha.6
@storybook/corenpm8.0.0 ≤ v < 8.6.198.6.19
@storybook/core-servernpm8.0.0 ≤ v < 8.6.198.6.19
@storybook/experimental-addon-testnpm8.0.0 ≤ v < 8.6.198.6.19
@storybook/addon-vitestnpm9.0.0 ≤ v < 9.1.21, 10.0.0 ≤ v < 10.6.2, 11.0.0-alpha.0 ≤ v < 11.0.0-alpha.69.1.21, 10.6.2, 11.0.0-alpha.6
@storybook/addon-mcpnpm10.6.0 ≤ v < 10.6.2, 11.0.0-alpha.0 ≤ v < 11.0.0-alpha.610.6.2, 11.0.0-alpha.6

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.

CVE-2026-114126 · Storybook · Dark Radar