MAL-2026-3811 Malicious code in claude-code-base-action (npm)
Malicious package
Published
MAL-2026-3811 is a malicious package: claude-code-base-action (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-3811/ (Markdown: https://insights.sbomify.com/MAL-2026-3811/index.md)
- Package
- claude-code-base-action
- Registry
- npm
What is MAL-2026-3811?
MAL-2026-3811 is a malicious package in claude-code-base-action, published on 17 May 2026.
Official description
The package claude-code-base-action was found to contain malicious code.
The OpenSSF Package Analysis project identified 'claude-code-base-action' @ 2.0.0 (npm) as malicious.
It is considered malicious because:
- The package communicates with a domain associated with malicious activity.
What should I do about MAL-2026-3811?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.