CVE-2026-45321

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…

Browse: All 2026 CVEs · All vendors

CVSS score
9.6 Critical
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CISA KEV
Yes — actively exploited (added 2026-05-27, remediation due 2026-06-10)
Ransomware
Known ransomware campaign use
Weakness (CWE)
CWE-506
Published
2026-05-12
Last modified
2026-06-17
NVD status
Analyzed

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 versions, published a few minutes apart.

Affected products

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

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. Federal remediation deadline: 2026-06-10.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score.

References

FAQ

Is CVE-2026-45321 actively exploited?

Yes. CISA added CVE-2026-45321 to its Known Exploited Vulnerabilities (KEV) catalog on 2026-05-27, with a federal remediation deadline of 2026-06-10. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

What is the CVSS score of CVE-2026-45321?

CVE-2026-45321 has a CVSS base score of 9.6 (Critical). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.