CVE-2026-45321

Name of the Vulnerable Software and Affected Versions @tanstack/* packages (affected versions not specified)

Description An attacker published 84 malicious versions across 42 @tanstack/* packages to the npm registry. The attack was executed by chaining a pull request target misconfiguration, GitHub Actions cache poisoning, and runtime memory extraction of an OIDC token from the Actions runner process to publish malware under a trusted identity. This resulted in the distribution of a self-propagating credential-stealing worm.

Upon installation, the malware executes an obfuscated JavaScript file named router init.js (approximately 2.3 MB) located at the package root. This payload harvests sensitive data from AWS instance metadata (IMDS), GCP metadata services, Kubernetes service-account tokens, HashiCorp Vault tokens, ~/.npmrc npm tokens, GitHub tokens, and SSH private keys. The stolen data is exfiltrated via the Session/Oxen messenger network using endpoints such as filev2.getsession.org and seed{1,2,3}.getsession.org.

Additionally, the worm can establish persistence in Claude Code and Microsoft Visual Studio Code (VS Code), install a gh-token-monitor service to steal GitHub tokens, and deploy malicious GitHub Actions workflows to exfiltrate repository secrets to api.masscan.cloud. It also attempts to spread by identifying other packages maintained by the victim and republishing them with the same injection. Tens of thousands of systems are estimated to be compromised.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Pin every @tanstack/* dependency to a known-good version published before 2026-05-11 19:00 UTC.

Delete node modules and the lockfile, then reinstall to ensure no transitive dependency resolves to a malicious version.

Configure npm to skip lifecycle scripts on install by using npm config set ignore-scripts true as a temporary defense-in-depth measure.

Verify the authenticity of npm packages before installation.

Rotate all credentials, secrets, and tokens accessible to any developer or CI environment that performed an installation of @tanstack/* packages on 2026-05-11.