[KEV] Vulnerability in TanStack (CVE-2026-45321)
Summary
Vulnerability in TanStack (CVE-2026-45321). Successful exploitation can lead to full system takeover. Exploitable via pull_request_target. Listed in CISA KEV — actively exploited. Mitigation: upgrade to 1.166.16 or later.
Original description
The description as published by the source.
Summary
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.
Impact
A user installing any affected version executes a payload (~2.3 MB obfuscated router_init.js) at install time that:
- Harvests credentials from common locations:
- AWS instance metadata (IMDS) and Secrets Manager
- GCP metadata service
- Kubernetes service-account tokens
- HashiCorp Vault tokens
~/.npmrc(npm tokens)- GitHub tokens (env vars,
ghCLI config,.git-credentials) - SSH private keys (
~/.ssh/)
- Exfiltrates harvested data over the Session/Oxen messenger file-upload network (
filev2.getsession.org,seed{1,2,3}.getsession.org). This is end-to-end encrypted with no attacker-controlled C2, so blocking by IP or domain is the only network mitigation. - Enumerates packages that the victim m…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory CISA KEV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-45321 has been found in TanStack.
Attackers can target a specific entry point like pull_request_target over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.6/10.
Note: CISA has officially confirmed this is actively exploited in the wild. Treat it with elevated urgency.
What to do: upgrade TanStack to 1.166.16 or later.
If unsure, ask your IT team or search "TanStack CVE-2026-45321" on the vendor's site.
CVE-2026-45321 (TanStack) — CVSS v3 9.6
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: pull_request_target / router_init.js / filev2.getsession.org / optionalDependencies
Patched: 1.166.16 — apply immediately
Listed in CISA KEV — actively exploited, treat as top priority.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in TanStack. Attackers reach the vulnerable code path via pull_request_target without authentication.
Check the vendor advisory for the affected versions of TanStack. Attack surface: pull_request_target / router_init.js / filev2.getsession.org / optionalDependencies.
Severity: Critical (CVSS 9.6/10). Successful exploitation can lead to full system takeover. Listed in CISA KEV — actively exploited in the wild, treat as top priority.
Update to 1.166.16.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@tanstack/arktype-adapter' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@tanstack/arktype-adapter' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@tanstack/arktype-adapterを grep し、稼働しているサービス・バージョンを把握する。 -
2Consider incident declaration escalate
Notify SOC / on-callCISA KEV登録済 = 実環境で悪用が観測されている。侵入の兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。
-
3Apply patch patch
Upgrade TanStack to 1.166.16ステージング環境で 1.166.16 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory NVD
- package github.com
- web github.com
- web github.com
- web socket.dev
- web github.com
- web tanstack.com
- web stepsecurity.io
- web cisa.gov