MalwarePublished 7 Apr 2026Updated 8 Jul 2026

@langgraphjs/toolkit (npm) · Malicious Code

Affects @langgraphjs/toolkitSource GCVE Database

Malicious package : remove @langgraphjs/toolkit and rotate any secrets on hosts that installed it.

Data as of 26 Oct 2026, 15:55 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-2509

What to do

Remove @langgraphjs/toolkit from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npm@langgraphjs/toolkit	Affected 1.2.10 – 1.2.13 4 affected builds	Fixed in–

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Description

The npm package @langgraphjs/toolkit versions 1.2.10 and 1.2.11 contains malicious code that executes a postinstall script to collect sensitive system information and exfiltrate it to a hardcoded external server. The package impersonates the LangChain/LangGraph ecosystem to deceive users. The exfiltrated data includes hostname, OS username, current working directory, git committer email, and GitHub login/email, violating user consent and privacy. Installation of this package may lead to full system compromise, requiring immediate secret and key rotation and package removal.

Impact

Installation of the affected versions of @langgraphjs/toolkit results in unauthorized exfiltration of sensitive system and user identity information to an attacker-controlled server. This breach of confidentiality can lead to full system compromise. The malicious package may allow attackers to gain control over the affected computer, exposing all stored secrets and keys. Consequently, any secrets or credentials on the compromised system should be considered exposed and rotated immediately. Removal of the package alone does not guarantee remediation due to potential persistence of other malicious components.

Defensive guidance

The recommended mitigation is to immediately remove the @langgraphjs/toolkit package versions 1.2.10 and 1.2.11 from all affected systems. All secrets, keys, and credentials stored on compromised machines should be rotated from a secure, uncompromised environment. Users should avoid installing packages that impersonate trusted ecosystems and verify package authenticity before installation. Monitor for any suspicious activity resulting from this compromise.

Summary

The @langgraphjs/toolkit npm package versions 1.2.10 and 1.2.11 include a malicious postinstall script that harvests sensitive system and user identity information such as os.hostname(), os.userInfo().username, process.cwd(), git committer email from local git config files, and GitHub login/email from the GitHub CLI configuration. This data is sent via HTTPS POST to a hardcoded Google Cloud Run endpoint unrelated to the legitimate LangChain/LangGraph project. The package name and install instructions impersonate the official ecosystem to mislead users. The README falsely claims only anonymized data is transmitted, concealing the actual sensitive data exfiltration. This behavior constitutes namespace impersonation combined with consent-violating identity theft on install. The package compromises the host system's security and privacy.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jul 2026, 15:07 UTC

Technical details

References

Community reviews