# MAL-2026-6093: Malicious code in jwtmode (npm)


- **Type:** Malicious package
- **Package:** `jwtmode` (npm)
- **Published:** 18 Jun 2026

## 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.

## Fix prompt for AI coding agents

```text
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)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6093

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6093/
Summaries are generated and may contain mistakes; the official description above is the record.