Storybook: Missing origin validation in Storybook preview allows code injection from malicious websites

Storybook

Summary: A malicious website may be able to cause unauthorized file changes in a developer’s project while an affected Storybook development server is running. Under additional conditions, a changed file could be executed by a local runtime with the developer’s privileges. We are not aware of exploitation in the wild. Who is impacted?

Do this now

Install the update for your version: storybook → 10.6.2; @storybook/addon-vitest → 10.6.2; @storybook/addon-mcp → 10.6.2 (+6 more lines in Fix it).

Fix it

storybook npm

On 8.x?npm install storybook@8.6.19
On 9.x?npm install storybook@9.1.21
On 10.x?npm install storybook@10.6.2
On 11.xNo stable fix for 11.x yet (only 11.0.0-alpha.6)

@storybook/core npm

npm install @storybook/core@8.6.19

@storybook/core-server npm

npm install @storybook/core-server@8.6.19

@storybook/experimental-addon-test npm

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

@storybook/addon-vitest npm

On 9.x?npm install @storybook/addon-vitest@9.1.21
On 10.x?npm install @storybook/addon-vitest@10.6.2
On 11.xNo stable fix for 11.x yet (only 11.0.0-alpha.6)

@storybook/addon-mcp npm

On 10.x?npm install @storybook/addon-mcp@10.6.2
On 11.xNo stable fix for 11.x yet (only 11.0.0-alpha.6)

First seen: 21 Oct 2026
Last update: 26 Oct 2026, 19:18 UTC
Fixed in: storybook 11.0.0-alpha.6
storybook 10.6.2
storybook 9.1.21
storybook 8.6.19
Identifiers: CVE-2026-114125
CVSS: 8.6
Source: GitHub advisory
On the menu as: npm packages

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Storybook: Missing origin validation in Storybook preview allows code injection from malicious websites
Severity: high. Patch status: patched.
Affected: Storybook
Fixed in: storybook 11.0.0-alpha.6, storybook 10.6.2, storybook 9.1.21, storybook 8.6.19
Ids: CVE-2026-114125

Summary: A malicious website may be able to cause unauthorized file changes in a developer’s project while an affected Storybook development server is running. Under additional conditions, a changed file could be executed by a local runtime with the developer’s privileges. We are not aware of exploitation in the wild. Who is impacted?

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `storybook`, `@storybook/core`, `@storybook/core-server`, `@storybook/experimental-addon-test`, `@storybook/addon-vitest`, `@storybook/addon-mcp`. For each hit, compare the installed version with the fix on the same major line: storybook 11.0.0-alpha.6, storybook 10.6.2, storybook 9.1.21, storybook 8.6.19. If it's lower, give the exact upgrade command for the package manager this repo uses.

## Fix by release line
| Line | State | Fix | Until then |
|---|---|---|---|
| storybook 11.0.x | No stable fix (only rc) | 11.0.0-alpha.6 is a prerelease | restrict network access to it |
| storybook 10.0.x | fixed | 10.6.2 | — |
| storybook 9.0.x | fixed | 9.1.21 | — |
| storybook 8.0.x | fixed | 8.6.19 | — |
| @storybook/core >= 8.0.0 < 8.6.19 | fixed | 8.6.19 | — |
| @storybook/core-server >= 8.0.0 < 8.6.19 | fixed | 8.6.19 | — |
| @storybook/experimental-addon-test >= 8.0.0 < 8.6.19 | fixed | 8.6.19 | — |
| @storybook/addon-vitest 11.0.x | No stable fix (only rc) | 11.0.0-alpha.6 is a prerelease | restrict network access to it |
| @storybook/addon-vitest 10.0.x | fixed | 10.6.2 | — |
| @storybook/addon-vitest 9.0.x | fixed | 9.1.21 | — |
| @storybook/addon-mcp 11.0.x | No stable fix (only rc) | 11.0.0-alpha.6 is a prerelease | restrict network access to it |
| @storybook/addon-mcp 10.6.x | fixed | 10.6.2 | — |

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-114125") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/advisories/GHSA-f2ph-cmg5-wxc8 https://github.com/storybookjs/storybook/commit/243c06bf8f1e2f09446c44868ea100261e1374da https://github.com/storybookjs/storybook/commit/3be03ec6f11f4616471cebc3fc65c13e1bf8c178 https://github.com/storybookjs/storybook/pull/36726 https://github.com/storybookjs/storybook/security/advisories/GHSA-f2ph-cmg5-wxc8
https://pwned.coffee/i/storybook-missing-origin-validation-in-storybook-preview-cve-2026-114125

Receipt

Exploitation: No known exploitation
Fix by release line: Product Affected Fixed in Source
storybook (npm) >= 11.0.0-alpha.0, < 11.0.0-alpha.6 11.0.0-alpha.6 GitHub advisory checked 26 Oct
storybook (npm) >= 10.0.0, < 10.6.2 10.6.2 GitHub advisory checked 26 Oct
storybook (npm) >= 9.0.0, < 9.1.21 9.1.21 GitHub advisory checked 26 Oct
storybook (npm) >= 8.0.0, < 8.6.19 8.6.19 GitHub advisory checked 26 Oct
@storybook/core (npm) >= 8.0.0, < 8.6.19 8.6.19 GitHub advisory checked 26 Oct
@storybook/core-server (npm) >= 8.0.0, < 8.6.19 8.6.19 GitHub advisory checked 26 Oct
@storybook/experimental-addon-test (npm) >= 8.0.0, < 8.6.19 8.6.19 GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm) >= 11.0.0-alpha.0, < 11.0.0-alpha.6 11.0.0-alpha.6 GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm) >= 10.0.0, < 10.6.2 10.6.2 GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm) >= 9.0.0, < 9.1.21 9.1.21 GitHub advisory checked 26 Oct
@storybook/addon-mcp (npm) >= 11.0.0-alpha.0, < 11.0.0-alpha.6 11.0.0-alpha.6 GitHub advisory checked 26 Oct
@storybook/addon-mcp (npm) >= 10.6.0, < 10.6.2 10.6.2 GitHub advisory checked 26 Oct
Score: CVSS 8.6 (high). CVSS 4.0 8.6 (CNA GitHub_M) for CVE-2026-114125
Last checked: 26 Oct 2026, 20:41 UTC

Product	Affected	Fixed in	Source
storybook (npm)	>= 11.0.0-alpha.0, < 11.0.0-alpha.6	11.0.0-alpha.6	GitHub advisory checked 26 Oct
storybook (npm)	>= 10.0.0, < 10.6.2	10.6.2	GitHub advisory checked 26 Oct
storybook (npm)	>= 9.0.0, < 9.1.21	9.1.21	GitHub advisory checked 26 Oct
storybook (npm)	>= 8.0.0, < 8.6.19	8.6.19	GitHub advisory checked 26 Oct
@storybook/core (npm)	>= 8.0.0, < 8.6.19	8.6.19	GitHub advisory checked 26 Oct
@storybook/core-server (npm)	>= 8.0.0, < 8.6.19	8.6.19	GitHub advisory checked 26 Oct
@storybook/experimental-addon-test (npm)	>= 8.0.0, < 8.6.19	8.6.19	GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm)	>= 11.0.0-alpha.0, < 11.0.0-alpha.6	11.0.0-alpha.6	GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm)	>= 10.0.0, < 10.6.2	10.6.2	GitHub advisory checked 26 Oct
@storybook/addon-vitest (npm)	>= 9.0.0, < 9.1.21	9.1.21	GitHub advisory checked 26 Oct
@storybook/addon-mcp (npm)	>= 11.0.0-alpha.0, < 11.0.0-alpha.6	11.0.0-alpha.6	GitHub advisory checked 26 Oct
@storybook/addon-mcp (npm)	>= 10.6.0, < 10.6.2	10.6.2	GitHub advisory checked 26 Oct

Sources: KEV – CVE record ✓ Vendor –

Sources

Wrong fix version, or a source we missed? Send it back to chef@pwned.coffee with the source, and we'll correct it here.

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