TanStack

A critical type confusion vulnerability, CVE-2026-59940, in `seroval.fromJSON()` versions prior to 1.5.3 allows attackers to provide malicious JSON input that misleads Promise control nodes into operating on attacker-controlled values, potentially leading to arbitrary method invocation and remote code execution or server compromise in downstream server frameworks like TanStack Start that deserialize untrusted input with plugins enabled.

Tracking brief for the Shai-Hulud campaign; individual sightings are folded in as reported.

The Shai-Hulud malware was used in a large-scale software supply-chain attack compromising hundreds of packages across open-source software ecosystems by compromising developer secrets and CI/CD pipelines.

The Mini Shai-Hulud supply chain campaign, attributed to TeamPCP, has compromised several npm packages, including those within the @tanstack, @uipath, and @mistralai namespaces, leading to credential theft and potential further compromise.

On 2026-05-11, multiple malicious versions of `@tanstack/*` packages were published to the npm registry due to a chained attack exploiting vulnerabilities in GitHub Actions; the attacker used a compromised GitHub Actions OIDC trusted-publisher binding to publish credential-stealing malware that harvests credentials, exfiltrates data, and propagates the compromise by republishing other packages with the same injection, requiring users who installed affected versions to consider their environment compromised and rotate all credentials.