CVE-2026-45321
Published: 12 May 2026
Summary
CVE-2026-45321 is a critical-severity Embedded Malicious Code (CWE-506) vulnerability in Tanstack (inferred from references). Its CVSS base score is 9.6 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Compromise Software Dependencies and Development Tools (T1195.001); ranked at the 11.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Restricting software to licensed versions and controlling P2P prevents introduction of software containing embedded malicious code from unauthorized sources.
The control prevents users from installing software that contains embedded malicious code.
Regular inventory reviews and updates make it harder to conceal or exploit embedded malicious code by requiring all components to be documented and accounted for.
Reverting to a known state removes any malicious code embedded by an attacker.
The approval and review process for maintenance tools can prevent introduction or continued use of tools containing embedded malicious code.
Supply chain strategy requires vetting and controls during acquisition to prevent or detect insertion of malicious code by vendors or integrators.
Background screening for development or deployment roles makes intentional insertion of malicious code by insiders materially harder to accomplish.
The capability explicitly searches for embedded malicious code and backdoors as indicators of compromise.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct supply-chain compromise of npm packages via poisoned CI/CD publish workflow and stolen OIDC token.
NVD 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…
more
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.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)