Is this vulnerability remotely exploitable beyond localhost?

Yes, if the Storybook dev server is exposed on a network (for example, for design reviews), any unauthenticated attacker who can reach the server can send malicious WebSocket messages directly. When the dev server is only on localhost, exploitation still becomes possible if a developer visits a malicious site that silently talks to the local server via WebSockets.

What level of access does an attacker need?

When the dev server is only locally bound, the attacker needs to lure a developer into visiting a malicious web page while the server is running. If the dev server is publicly reachable, no prior authentication or user interaction is required; the attacker only needs network access to the dev server endpoint.

What is the safest general fix pattern?

The safest pattern is to treat the dev server like a production service for security-sensitive operations: enforce WebSocket origin validation and/or authentication, strictly validate and sanitize all user-controlled fields before using them for file or code generation, and confine file write operations to a controlled workspace with restricted capabilities.

Severity:

CRITICAL RISK

(9.6)

WebSocket Input Injection & Persistent XSS (CWE-74/CWE-79) in Storybook Dev Server

CVE-2026-27148

Published:

Feb 25, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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HIGH

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May 6, 2026

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HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Privilege Escalation via Bypassed Access Control

May 6, 2026

Vulnerability Type

Category:

Input Injection & Cross-Site Scripting

CWE:

CWE-74;CWE-79

Impact:

Persistent Cross-Site Scripting and Remote Code Execution in Development Environments

Severity:

CRITICAL RISK

(9.6)

CVSS Version:

3.1

Vulnerability Type

Category:

Input Injection & Cross-Site Scripting

CWE:

CWE-74;CWE-79

Impact:

Persistent Cross-Site Scripting and Remote Code Execution in Development Environments

Severity:

CRITICAL RISK

(9.6)

CVSS Version:

3.1

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WebSocket Input Injection & Persistent XSS (CWE-74/CWE-79) in Storybook Dev Server

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.6)

Server-Side Request Forgery (CWE-918) in OpenClaw Zalo Plugin sendPhoto

HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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