CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Called exploited 15 days after disclosure.
Measured from the CVE publication date to the earliest of 3 KEV catalogues that list it.
The life of this vulnerability
- CVE published
- First KEV listing15d
- Last sighting36d
Gaps are compressed to equal steps. The elapsed time is printed under each.
Which catalogues call it exploited
- CISA KEVUS federallisted May 27, 2026
- EUVDENISA, European Unionlisted May 27, 2026
- VulnCheck KEVcommercial researchlisted May 27, 2026
- CIRCLaggregator, mirrors the abovelisted May 27, 2026, not counted
3 catalogues list it. CIRCL aggregates the others and is shown but not counted.
Public exploitation evidence
- reported exploitationwww.ic3.gov/CSA/2026/260702.pdf
- reported exploitationnefariousplan.com/posts/tanstack-cve-2026-45321-bundle-size-
- reported exploitationvulnerability.circl.lu/known-exploited-vulnerabilities-catal
- reported exploitationwww.cisa.gov/sites/default/files/feeds/known_exploited_vulne
4 public reports collected from VulnCheck and CIRCL, first on May 27, 2026. Each links to its original source. We have not verified them.
Description
On 2026-05-11, between approximately 19:20 and 19:26 UTC, 84 malicious versions across 42 @tanstack/* packages were published to the npm registry. The publishes were authenticated via the legitimate GitHub Actions OIDC trusted-publisher binding for TanStack/router, but the publish workflow itself was not modified. The attacker chained three known vulnerability classes — a pull_request_target "Pwn Request" misconfiguration, GitHub Actions cache poisoning across the fork↔base trust boundary, and runtime memory extraction of the OIDC token from the Actions runner process — to publish credential-stealing malware under a trusted identity. Each affected package received exactly two malicious versi
Required action (CISA)
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.