9.3
CRITICAL CVSS 3.1
CVE-2026-102989
TanStack Router: Unauthenticated reflected XSS in TanStack Start server-function responses
Description

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.

INFO

Published Date :

Oct. 13, 2026, 5:17 p.m.

Last Modified :

Oct. 13, 2026, 5:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-102989 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL MITRE-CVE
CVSS 3.1 CRITICAL [email protected]
Solution
Update affected TanStack Router packages to patched versions to prevent response injection.
  • Update @tanstack/start-server-core to 1.169.39 or later.
  • Update @tanstack/react-start to 1.168.60 or later.
  • Update @tanstack/solid-start to 1.168.57 or later.
  • Update @tanstack/vue-start to 1.168.56 or later.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-102989 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-102989 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-102989 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-102989 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 13, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
    Added CWE CWE-79
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102989.json">CVE-2026-102989</a>
    Added Reference https://github.com/TanStack/router/commit/d521abd71c69f1ff010bb3def4d417cb5fa058cb
    Added Reference https://github.com/TanStack/router/pull/8573
    Added Reference https://github.com/TanStack/router/releases/tag/release-2026-09-30-1747
    Added Reference https://github.com/TanStack/router/security/advisories/GHSA-qx66-fv34-fjm8
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.