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Actively exploitedKnown ransomware use

CVE-2026-45321 TanStack Unspecified Vulnerability

TanStack contains an unspecified vulnerability that allowed malicious versions of the product to be published to the npm registry to publish credential-stealing malware under a trusted identity.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 27 May 2026.
  • CISA lists it as known to be used in ransomware campaigns.
  • Rated Critical severity (CVSS 9.6, scored by Vendor).
  • It has been in the catalogue for 163 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

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 Versions

ProductVersions
@tanstack arktype-adapter1.166.12
1.166.15
@tanstack eslint-plugin-router1.161.9
1.161.12
@tanstack eslint-plugin-start0.0.4
0.0.7
@tanstack history1.161.9
1.161.12
@tanstack nitro-v2-vite-plugin1.154.12
1.154.15
@tanstack react-router1.169.5
1.169.8

From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for TanStack. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Vendor Advisories

Regulation

The Compliance Clock

Cyber EssentialsRated critical, so if it affects devices in your Cyber Essentials scope, the update must be installed within 14 days of the vendor releasing it.NIS2If exploitation causes a significant incident, essential and important entities owe their CSIRT an early warning within 24 hours and a notification within 72 hours.DORAFinancial entities must classify ICT incidents and send an initial notification for a major incident within strict deadlines, with exploited flaws a common cause.US federal (BOD 22-01)Federal civilian agencies had until 10 Jun 2026 to remediate. A sensible benchmark for everyone else.

General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.

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Evidence

Sources

  1. CISA Known Exploited Vulnerabilities catalogue
  2. NVD: CVE-2026-45321
  3. CVE record: CVE-2026-45321
  4. FIRST EPSS
  5. github.com/TanStack/router/security/advisories/GHSA-g7cv-rxg3-hmpx
  6. github.com/TanStack/router/issues/7383
  7. tanstack.com/blog/npm-supply-chain-compromise-postmortem
  8. stepsecurity.io/blog/mini-shai-hulud-is-back-a-self-spreading-supply-chain-attack-hits-the-npm-ecosy