Critical 9.3Published Oct 13, 2026

CVE-2026-102989TanStack Router: Unauthenticated reflected XSS in TanStack Start server-function responses

Updated under an hour ago (2026-10-19 09:50 UTC)

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It affects TanStack router and 4 other products. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.52%, higher than 43% of scored CVEs.

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Every CVE for TanStack router

Exploited in the last 30 days

TanStack Router is a client-first, server-capable, fully type-safe router and full-stack framework for the web. From 1.143.12 until 1.169.39 for @tanstack/start-server-core, 1.168.60 for @tanstack/react-start, 1.168.57 for @tanstack/solid-start, and 1.168.56 for @tanstack/vue-start, an unauthenticated attacker can place non-public fields in a server-function request payload so that attacker-controlled middleware state reaches the error path and a response-shaped object is accepted as an HTTP response. A crafted server-function URL can therefore return attacker-controlled HTML from the application's origin; when a visitor opens the URL, the injected script can access same-origin data and issue requests with the visitor's authority. This issue is fixed in @tanstack/start-server-core 1.169.39, @tanstack/react-start 1.168.60, @tanstack/solid-start 1.168.57, and @tanstack/vue-start 1.168.56.

CVSS: 9.3 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.52% (percentile 43)
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 13, 2026

Affected products

Affected products

TanStack router tanstack:router (from the name)	before release-2026-09-30-1747	CNA record
@tanstack react-start tanstack:react_start (from the name)	from 1.143.12, < 1.168.60	CNA record
@tanstack solid-start tanstack:solid_start (from the name)	from 1.143.12, < 1.168.57	CNA record
@tanstack start-server-core tanstack:start_server_core (from the name)	from 1.143.12, < 1.169.39	CNA record
@tanstack vue-start tanstack:vue_start (from the name)	from 1.143.12, < 1.168.56	CNA record

References

https://github.com/TanStack/router/security/advisories/GHSA-qx66-fv34-fjm8x-refsource-confirm
https://github.com/TanStack/router/pull/8573x-refsource-misc
https://github.com/TanStack/router/commit/d521abd71c69f1ff010bb3def4d417cb5fa058cbx-refsource-misc
https://github.com/TanStack/router/releases/tag/release-2026-09-30-1747x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.