CVE-2025-68429: Storybook Information Disclosure Flaw

CVE-2025-68429 Overview

CVE-2025-68429 is an Information Exposure vulnerability in Storybook, a popular frontend workshop for building user interface components and pages in isolation. The vulnerability relates to Storybook's improper handling of environment variables defined in .env files, which could lead to sensitive variables being unexpectedly bundled into build artifacts created by the storybook build command. When a built Storybook is published to the web, the bundle's source becomes viewable, potentially exposing sensitive secrets such as API keys, database credentials, or other configuration values to anyone with access to the deployed Storybook.

Critical Impact

Sensitive environment variables from .env files may be inadvertently exposed in publicly accessible Storybook builds, potentially leading to credential theft and unauthorized system access.

Affected Products

• Storybook versions 7.0.0 through 7.6.20
• Storybook versions 8.0.0 through 8.6.14
• Storybook versions 9.0.0 through 9.1.16
• Storybook versions 10.0.0 through 10.1.9

Discovery Timeline

• 2025-12-17 - CVE-2025-68429 published to NVD
• 2026-04-10 - Last updated in NVD database

Technical Details for CVE-2025-68429

Vulnerability Analysis

This vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) stems from Storybook's undocumented behavior in processing .env files during the build process. When executing storybook build, the tool inadvertently bundles environment variables from .env files (including variants like .env.local) into the final JavaScript artifacts. Since these bundles are client-side code, anyone can inspect the source and extract embedded environment variables.

The attack is network-accessible without any authentication requirements and does not require user interaction. An attacker simply needs to access the publicly deployed Storybook application and inspect the bundled JavaScript source code to extract any exposed secrets.

Root Cause

The root cause lies in Storybook's build pipeline which, in certain configurations, includes all environment variables from .env files in the final bundle rather than limiting inclusion to explicitly prefixed variables (such as STORYBOOK_). This behavior appears to have been an undocumented feature that some projects may have relied upon, but it creates a significant security risk when builds containing sensitive credentials are deployed publicly.

Attack Vector

The attack vector for CVE-2025-68429 is straightforward:

1. An organization builds their Storybook in a directory containing a .env file with sensitive secrets
2. The built Storybook is deployed to a web-accessible location
3. An attacker visits the deployed Storybook URL
4. The attacker uses browser developer tools to inspect the JavaScript bundle sources
5. Environment variables from the .env file are visible within the bundled code
6. The attacker extracts sensitive credentials such as API keys, database passwords, or third-party service tokens

This vulnerability specifically affects production builds created with storybook build. Development environments using storybook dev are not affected. Additionally, builds performed in CI environments where secrets are provided via platform environment variables (rather than .env files) are not vulnerable.

Detection Methods for CVE-2025-68429

Indicators of Compromise

• Review deployed Storybook JavaScript bundles for unexpected environment variable strings
• Search build artifacts for sensitive credential patterns (API keys, tokens, connection strings)
• Audit access logs for unusual inspection activity on Storybook static assets
• Check for unauthorized use of credentials that may have been exposed through Storybook builds

Detection Strategies

• Implement static analysis scanning on Storybook build outputs to detect embedded secrets
• Use secret scanning tools to analyze JavaScript bundles before deployment
• Configure CI/CD pipelines to fail builds if sensitive patterns are detected in output artifacts
• Monitor for credential usage from unexpected IP addresses or locations

Monitoring Recommendations

• Enable logging for all Storybook asset requests to detect reconnaissance activity
• Set up alerts for bulk downloads of JavaScript bundles from Storybook deployments
• Implement credential rotation alerts to track potential exposure events
• Monitor third-party service dashboards for suspicious authentication attempts using potentially exposed keys

How to Mitigate CVE-2025-68429

Immediate Actions Required

• Upgrade Storybook to version 7.6.21, 8.6.15, 9.1.17, or 10.1.10 on all local development machines and CI environments
• Audit all .env files in Storybook project directories for sensitive secrets
• Rotate any credentials that may have been exposed in previously deployed Storybook builds
• Review deployed Storybook instances and remove or rebuild those containing exposed secrets

Patch Information

Storybook has released patched versions that address this environment variable exposure vulnerability. Users should update to the following fixed versions:

• Version 7.x: Upgrade to 7.6.21 or later
• Version 8.x: Upgrade to 8.6.15 or later
• Version 9.x: Upgrade to 9.1.17 or later
• Version 10.x: Upgrade to 10.1.10 or later

For detailed information, refer to the GitHub Security Advisory GHSA-8452-54wp-rmv6 and the Storybook Blog Security Advisory.

Workarounds

• Remove .env files from Storybook build directories before running storybook build
• Migrate sensitive secrets from .env files to CI platform-specific environment variable storage
• If environment variables are needed in Storybook, prefix non-sensitive variables with STORYBOOK_ or use the env property in Storybook configuration
• Restrict access to deployed Storybook instances using authentication or network-level controls until patches can be applied

# Configuration example: Using Storybook's env property in main.js
# Only include non-sensitive configuration values
export STORYBOOK_API_BASE_URL="https://api.example.com"
export STORYBOOK_APP_NAME="MyApp"

# Remove sensitive variables from .env before building
# Move secrets to CI platform environment variable storage
rm -f .env .env.local .env.production

# Upgrade Storybook to patched version
npm update storybook@latest
# Or for specific version
npm install storybook@7.6.21