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

Advisory record · `GHSA-f2ph-cmg5-wxc8`

- **Identifiers:** `GHSA-f2ph-cmg5-wxc8` · `CVE-2026-114125`
- **State:** Confirmed
- **Severity:** CVSS 8.6 High
- **Critical:** No
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html) · [CWE-94](https://cwe.mitre.org/data/definitions/94.html) · [CWE-96](https://cwe.mitre.org/data/definitions/96.html) · [CWE-346](https://cwe.mitre.org/data/definitions/346.html) · [CWE-441](https://cwe.mitre.org/data/definitions/441.html) · [CWE-749](https://cwe.mitre.org/data/definitions/749.html) · [CWE-862](https://cwe.mitre.org/data/definitions/862.html) · [CWE-1021](https://cwe.mitre.org/data/definitions/1021.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md) · [Code injection](https://agentprime.io/advisories/tag/code-injection.md) · [Broken access control](https://agentprime.io/advisories/tag/access-control.md) · [CWE-346](https://agentprime.io/advisories/tag/cwe-346.md) · [CWE-441](https://agentprime.io/advisories/tag/cwe-441.md) · [CWE-749](https://agentprime.io/advisories/tag/cwe-749.md) · [CWE-1021](https://agentprime.io/advisories/tag/cwe-1021.md)
- **Published:** 21 Oct 2026
- **Updated:** 21 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 21 Oct 2026, 17:23 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `storybook` (npm): affected `>=8.0.0, <8.6.19 || >=9.0.0, <9.1.21 || >=10.0.0, <10.6.2 || >=11.0.0-alpha.0, <11.0.0-alpha.6`; fixed in `8.6.19`, `9.1.21`, `10.6.2`, `11.0.0-alpha.6`
- `@storybook/core` (npm): affected `>=8.0.0, <8.6.19`; fixed in `8.6.19`
- `@storybook/core-server` (npm): affected `>=8.0.0, <8.6.19`; fixed in `8.6.19`
- `@storybook/experimental-addon-test` (npm): affected `>=8.0.0, <8.6.19`; fixed in `8.6.19`
- `@storybook/addon-vitest` (npm): affected `>=9.0.0, <9.1.21 || >=10.0.0, <10.6.2 || >=11.0.0-alpha.0, <11.0.0-alpha.6`; fixed in `9.1.21`, `10.6.2`, `11.0.0-alpha.6`
- `@storybook/addon-mcp` (npm): affected `>=10.6.0, <10.6.2 || >=11.0.0-alpha.0, <11.0.0-alpha.6`; fixed in `10.6.2`, `11.0.0-alpha.6`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.6 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0039, the 32nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:33 UTC: First seen by agentprime
- 31 Oct 2026, 13:33 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-f2ph-cmg5-wxc8)

## Sources

- [GitHub Advisory Database: GHSA-f2ph-cmg5-wxc8](https://github.com/advisories/GHSA-f2ph-cmg5-wxc8)
- [OSV: GHSA-f2ph-cmg5-wxc8](https://osv.dev/vulnerability/GHSA-f2ph-cmg5-wxc8)
- <https://github.com/storybookjs/storybook/security/advisories/GHSA-f2ph-cmg5-wxc8>
- <https://github.com/storybookjs/storybook/pull/36726>
- <https://github.com/storybookjs/storybook/commit/243c06bf8f1e2f09446c44868ea100261e1374da>
- <https://github.com/storybookjs/storybook/commit/3be03ec6f11f4616471cebc3fc65c13e1bf8c178>
- <https://github.com/storybookjs/storybook/commit/a9ef9345d73224c73e0b81dc2701ec5b465ea9bb>
- <https://github.com/storybookjs/storybook/commit/d9b09e332510a88689c71ecc081bbbc2d072476e>
- <https://github.com/storybookjs/storybook/commit/df3fed468c9b4830605f00068c4bc6b7e1e215ed>
- <https://github.com/storybookjs/storybook>
- <https://github.com/storybookjs/storybook/releases/tag/v10.6.2>
- <https://github.com/storybookjs/storybook/releases/tag/v11.0.0-alpha.6>
- <https://github.com/storybookjs/storybook/releases/tag/v8.6.19>
- <https://github.com/storybookjs/storybook/releases/tag/v9.1.21>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-f2ph-cmg5-wxc8>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-f2ph-cmg5-wxc8/>. Everything for agents: <https://agentprime.io/llms.txt>.