Known exploited vulnerability
CVE-2026-45321
The short answer
CVE-2026-45321 affects @tanstack arktype-adapter and is rated critical (CVSS 9.6). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-05-27: attackers are using it, so patch it first. Fixed versions are published for @tanstack/arktype-adapter (1.166.16) and @tanstack/eslint-plugin-router (1.161.13).
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.
Weakness: CWE-506.
Severity
9.6 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since May 27, 2026
Federal due date Jun 10, 2026
EPSS, next 30 days
3.3%
Higher than 89% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected packages and fixed versions
| Package | Ecosystem | Fixed in | Advisory |
|---|---|---|---|
| @tanstack/arktype-adapter | npm | 1.166.16 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/eslint-plugin-router | npm | 1.161.13 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/eslint-plugin-start | npm | 0.0.8 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/history | npm | 1.161.13 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/nitro-v2-vite-plugin | npm | 1.154.16 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-router | npm | 1.169.9 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-router-devtools | npm | 1.166.20 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-router-ssr-query | npm | 1.166.19 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-start | npm | 1.167.72 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-start-client | npm | 1.166.55 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-start-rsc | npm | 0.0.51 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/react-start-server | npm | 1.166.59 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-cli | npm | 1.166.50 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-core | npm | 1.169.9 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-devtools | npm | 1.166.20 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-devtools-core | npm | 1.167.10 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-generator | npm | 1.166.49 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-plugin | npm | 1.167.42 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-ssr-query-core | npm | 1.168.7 | GHSA-g7cv-rxg3-hmpx |
| @tanstack/router-utils | npm | 1.161.15 | GHSA-g7cv-rxg3-hmpx |
Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.
Affected products
arktype-adapter, eslint-plugin-router, eslint-plugin-start, history, nitro-v2-vite-plugin, react-router, react-router-devtools, react-router-ssr-query, react-start, react-start-client, react-start-rsc, react-start-server. NVD's record lists the exact affected versions.
References
- github.com/TanStack/router/issues/7383 Issue Tracking
- github.com/TanStack/router/security/advisories/GHSA-g7cv-rxg3-hmpx MitigationVendor Advisory
- tanstack.com/blog/npm-supply-chain-compromise-postmortem ExploitVendor Advisory
- www.stepsecurity.io/blog/mini-shai-hulud-is-back-a-self-spreading-supply-chain-attack-hits-the-npm-ecosystem ExploitThird Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45321 US Government Resource
Questions
Is CVE-2026-45321 being exploited?
Yes. CISA added CVE-2026-45321 to its Known Exploited Vulnerabilities catalog on 2026-05-27, with a federal remediation due date of 2026-06-10. CISA lists it as used in ransomware campaigns.
How do I fix CVE-2026-45321?
Upgrade to a fixed version: @tanstack/arktype-adapter (npm) 1.166.16; @tanstack/eslint-plugin-router (npm) 1.161.13; @tanstack/eslint-plugin-start (npm) 0.0.8; @tanstack/history (npm) 1.161.13. CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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