Security readout for executives and security teams
Plain-English summary
Attackers published 84 credential-stealing releases across 42 legitimate @tanstack packages during a six-minute window. Organizations that installed or executed those versions may have exposed cloud credentials, GitHub tokens, SSH keys, and other sensitive data. Because publication used TanStack’s trusted identity, ordinary publisher-trust checks were insufficient.
Executive priority
Immediate. Inventory affected dependencies, isolate impacted build environments, and begin credential rotation today. Treat confirmed installation or execution as a potential credential compromise, not merely a vulnerable dependency. Prioritize environments holding production cloud access, publishing permissions, source-code access, or SSH credentials.
Technical view
The attacker reportedly chained an unsafe pull_request_target workflow, cross-boundary GitHub Actions cache poisoning, and runtime extraction of an OIDC token. This enabled authenticated npm publication through the legitimate trusted-publisher binding without modifying the publishing workflow. Each affected package received two malicious versions.
Likely exposure
Exposure requires checking dependency manifests, lockfiles, package-manager caches, build records, containers, and deployed artifacts for the exact malicious versions. Systems where an affected release was installed or executed with access to developer, CI, cloud, GitHub, or SSH credentials warrant incident-response handling. The supplied affected list is incomplete, showing 20 of 42 packages.
Exploitation context
CISA KEV inclusion supports treating this as exploited in the wild. The source bundle describes an actual supply-chain compromise on May 11, 2026, rather than a theoretical weakness. Evidence does not establish which downstream organizations were compromised or whether every installation resulted in credential theft.
Researcher notes
The trusted OIDC publication identity does not prove package integrity because the runner token was reportedly extracted at runtime. Investigation should correlate package resolution timestamps with CI execution, credential access, and subsequent authentication events. Obtain the complete 42-package version list from the advisory; the supplied structured affected section contains only 20 packages.
Mitigation direction
- Remove or replace every identified malicious package version using current TanStack guidance.
- Rotate credentials accessible to affected developer, CI, build, and deployment environments.
- Revoke exposed GitHub tokens, cloud credentials, SSH keys, and active sessions.
- Rebuild affected artifacts from a verified clean dependency set and trusted environment.
- Review TanStack and CISA guidance for additional packages or remediation updates.
Validation and detection
- Search manifests and lockfiles for every malicious package and version listed by TanStack.
- Inspect package caches, build logs, containers, and deployed artifacts for affected releases.
- Review GitHub, cloud, SSH, and CI audit logs for suspicious credential use.
- Confirm revoked credentials no longer authenticate and replacements are stored securely.
- Verify rebuilt artifacts resolve only to versions TanStack identifies as clean.
Public sources used
The source record changed after analysis: Material source record changed after analysis.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-506: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-45321 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.6 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H2.86GitHub_MVulnerability scoring details
Base CVSS 3.1 score
9.6CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2026-45321 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-05-27T00:00:00.000Z: CVE-2026-45321 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/TanStack/router/security/advisories/GHSA-g7cv-rxg3-hmpxCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/TanStack/router/issues/7383CVE reference, GitHub_M · x_refsource_MISC
- https://tanstack.com/blog/npm-supply-chain-compromise-postmortemCVE reference, GitHub_M · x_refsource_MISC
- https://www.stepsecurity.io/blog/mini-shai-hulud-is-back-a-self-spreading-supply-chain-attack-hits-the-npm-ecosystemCVE reference, GitHub_M · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45321CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Embedded Malicious Code
Embedded Malicious Code represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.