CVE-2026-114126 Storybook dev server: devices on the same network can obtain the WebSocket token and write code into story files

What is CVE-2026-114126?

CVE-2026-114126 is a high-severity vulnerability in storybookjs storybook, published on 21 Oct 2026.

Official 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.

Weakness: CWE-94, CWE-306, CWE-22

Which versions are affected by CVE-2026-114126?

24 open source packages ship an affected version, including storybook, @storybook/addon-mcp and @storybook/addon-vitest.

How do I fix CVE-2026-114126?

Upgrade storybook to a fixed version for your release line: 10.6.2, 11.0.0-alpha.6, 8.6.19 or 9.1.21.

Is CVE-2026-114126 being exploited?

There is no known exploitation of CVE-2026-114126 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-px85-f4q5-jh77, ROOT-APP-NPM-CVE-2026-114126.