Storybook is a widely used frontend development tool that allows developers to build UI components in isolation. The vulnerability CVE-2025-68429 arises from how Storybook handles environment variables defined in .env files during the build process. Specifically, when running the `storybook build` command in a directory containing a .env file (or its variants like .env.local), Storybook may inadvertently bundle these environment variables into the static artifacts it generates. Since these artifacts are often published to the web for sharing or documentation purposes, the bundled source code becomes accessible to anyone with access to the published Storybook, thereby exposing sensitive environment variables such as API keys, tokens, or other secrets. This exposure violates confidentiality and can lead to further exploitation if attackers leverage the leaked secrets. The vulnerability affects multiple Storybook versions starting from 7.0.0 up to versions prior to 7.6.21, 8.6.15, 9.1.17, and 10.1.10. Notably, Storybook runtime environments (e.g., `storybook dev`) and deployed applications sharing the repository are not impacted. The issue is conditional on the presence of a .env file during build time and the public availability of the built Storybook. The maintainers recommend upgrading to patched versions immediately, auditing for any exposed secrets, and rotating them. Additionally, projects relying on the previous undocumented behavior of environment variable handling will need to adjust their configuration, such as prefixing variables with `STORYBOOK_` or using the `env` property in Storybook’s config, while avoiding inclusion of sensitive secrets in the build. The CVSS v3.1 score of 7.3 reflects a high severity due to network exploitable, no privileges required, no user interaction, and impact on confidentiality, integrity, and availability.

For European organizations, this vulnerability poses a significant risk of sensitive information leakage, especially for companies that use Storybook to document or share UI components publicly or within semi-public environments. Exposure of environment variables can lead to unauthorized access to backend services, APIs, or cloud resources, potentially resulting in data breaches, service disruptions, or further lateral movement within corporate networks. Organizations in sectors with strict data protection regulations such as GDPR (e.g., finance, healthcare, and critical infrastructure) face increased compliance risks and potential fines if sensitive data is leaked. The impact is heightened for companies that embed secrets directly in .env files rather than using secure vaults or CI environment variables. Since Storybook is popular among frontend development teams across Europe, the risk is widespread, particularly for organizations that do not segregate build environments or restrict access to published Storybook instances. The vulnerability could also undermine trust in software supply chains if leaked secrets enable attackers to compromise downstream applications or services.

European organizations should immediately upgrade all Storybook instances—both local development environments and CI/CD pipelines—to versions 7.6.21, 8.6.15, 9.1.17, or 10.1.10 or later. Audit all existing Storybook builds for the presence of sensitive environment variables in published artifacts and rotate any exposed secrets promptly. Avoid using .env files containing secrets during the build process; instead, use CI/CD environment variables or secret management solutions that do not write secrets to disk. Review and update Storybook configurations to use the `env` property or prefix environment variables with `STORYBOOK_` to prevent accidental bundling. Restrict access to published Storybook instances by implementing authentication and network controls, especially if public exposure is not required. Integrate automated scanning of built Storybook artifacts in CI pipelines to detect accidental inclusion of sensitive data. Educate development teams about the risks of embedding secrets in frontend build processes and enforce best practices for secret management. Finally, monitor for any suspicious activity that could indicate exploitation attempts leveraging leaked secrets.