MAL-2026-6093 Malicious code in jwtmode (npm)
Malicious package
Published
MAL-2026-6093 is a malicious package: jwtmode (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-2026-6093/ (Markdown: https://insights.sbomify.com/MAL-2026-6093/index.md)
- Package
- jwtmode
- Registry
- npm
What is MAL-2026-6093?
MAL-2026-6093 is a malicious package in jwtmode, published on 18 Jun 2026.
Official description
On require('jwtmode'), decode.js immediately invokes getThirdCookie(), which performs an HTTP GET to https://jsonkeeper.com/b/AZ9ZF, takes the response field response.data.errCode, passes it to
new Function.constructor('require', errCode), and invokes the resulting function with the real Node require. This is unconditional remote code execution at import time from a mutable, attacker-controlled paste host, with full Node capability (filesystem, network, child_process) via require. The package additionally impersonates auth0's jsonwebtoken: it is named jwtmode, declares author: auth0, points its repository field at a non-existent github.com/auth0/node-jwtmode, and re-exports jsonwebtoken's public API surface (decode, JsonWebTokenError, NotBeforeError, TokenExpiredError) — a brand-impersonation lure to trick developers into installing it instead of jsonwebtoken. Any project that requires jwtmode will execute whatever JavaScript the operator of jsonkeeper.com/b/AZ9ZF chooses to serve at that moment.What should I do about MAL-2026-6093?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.