CVE-2026-27148

What it is

Storybook is a frontend workshop for building user interface components and pages in isolation. Prior to versions 7.6.23, 8.6.17, 9.1.19, and 10.2.10, the WebSocket functionality in Storybook's dev server, used to create and update stories, is vulnerable to WebSocket hijacking. This vulnerability only affects the Storybook dev server; production builds are not impacted. Exploitation requires a developer to visit a malicious website while their local Storybook dev server is running. Because the WebSocket connection does not validate the origin of incoming connections, a malicious site can silently send WebSocket messages to the local instance without any further user interaction. If the Storybook dev server is intentionally exposed publicly (e.g. for design reviews or stakeholder demos) the risk is higher, as no malicious site visit is required. Any unauthenticated attacker can send WebSocket messages to it directly. The vulnerability affects the WebSocket message handlers for creating and saving stories. Both are vulnerable to injection via unsanitized input in the componentFilePath field, which can be exploited to achieve persistent XSS or Remote Code Execution (RCE). Versions 7.6.23, 8.6.17, 9.1.19, and 10.2.10 contain a fix for the issue.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.6% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-02-25 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-15 02:19 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.6% in the next 30 days (EPSS).
• Severity: 8.9 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-02-25 22:16 UTC

Last modified

2026-07-15 02:19 UTC

Exploit probability

0.6% · EPSS, next 30 days

Weakness

CWE-74

Record status

Modified

Affected

• Storybook < 7.6.23
• Storybook < 8.6.17
• Storybook < 9.1.19
• Storybook < 10.2.10

Attack profile CVSS 4.0 · 8.9

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Active

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-27148.md and follow it. Check whether this project is affected by CVE-2026-27148. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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