Threats / TanStack / CVE-2026-45321
CVE-2026-45321
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
TanStack vulnerability
TanStack vulnerability allowed malicious versions to be published to npm registry, distributing credential-stealing malware under a trusted identity.
Verdict
Today item, not a backlog item.
An unspecified vulnerability in TanStack's supply chain enabled attackers to publish compromised packages to npm, delivering credential theft malware to developers who installed the trojanized versions.
CISA KEV Yes · 2026-05-275Ransomware use Flagged5EPSS 0.02342 (verify live)6CVSS 9.63CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
4 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-27), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.02342 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.6 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H) · Affected: TanStack, TanStack. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-506 CWE-506.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 15 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
WeaknessCWE-506 · CWE-506
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I exploit a weakness in TanStack's publishing or authentication controls to gain unauthorized access to publish packages.
Business
Developers unknowingly install malicious TanStack versions, exposing credentials and enabling lateral movement into customer environments.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I publish credential-stealing malware under TanStack's trusted identity on npm, leveraging the brand's reputation to avoid detection.
Business
Supply chain compromise affects all downstream users of TanStack, creating widespread exposure across the JavaScript ecosystem.
3
Lateral reach — past segmentation narrative 3
Attacker
I harvest stolen credentials from infected developer machines and systems running the trojanized package.
Business
Attackers gain access to sensitive systems, intellectual property, and infrastructure, enabling ransomware deployment and data exfiltration.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05