CVE-2026-102989

validated

GHSA-qx66-fv34-fjm8 ↗EUVD-2026-98849 ↗

check availablenot proven exploitable

cve.org+12dpublic pockev

npm:@tanstack/start-server-core >= 1.143.12, < 1.169.39; >= 1.143.12, < 1.168.60; >= 1.143.12, < 1.168.57; >= 1.143.12, < 1.168.56

fixed in 1.169.39, 1.168.60, 1.168.57, 1.168.56

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

ETK-2026-261, permanent identifier

pkg:npm/@tanstack/start-server-core

pkg:npm/@tanstack/react-start

pkg:npm/@tanstack/solid-start

pkg:npm/@tanstack/vue-start

cvss9.3cna vendorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

−12dTTV

22mAI analysis

Check if you are vulnerable

timeline

0 = cve.org publication

trigger signal −13dcheck available−12dagent stoppedcve.org publication

−10d

−5d

description

Affected TanStack Start server-function packages can return attacker-controlled HTML from an application's origin. An unauthenticated attacker can target a server-function URL; exploitation requires a victim to open the crafted link, after which script may access same-origin data and act with that visitor's permissions.

mitigation

Upgrade @tanstack/start-server-core to 1.169.39, @tanstack/react-start to 1.168.60, @tanstack/solid-start to 1.168.57, or @tanstack/vue-start to 1.168.56, as applicable. Until upgraded, restrict requests to configured server-function paths with tested edge or WAF rules and apply a restrictive CSP to server-function responses.

fixed in 1.169.39, 1.168.60, 1.168.57, 1.168.56

check

available

exploit

automation

contextual

auth required

EPSS

0.52%42nd percentile

agent run time

22m

cve.org record, t = 0

2026-10-13 16:13Z

Δ to public poc

–

Δ to kev

–

outcome

Mechanism verified: the exploit fired on the vulnerable build and stayed silent on the patched one, but the server it ran against was ours, so no check ships for it.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

2026-09-30 17:57Z
ghsa: trigger signal, started the run
https://github.com/TanStack/router/security/advisories/GHSA-qx66-fv34-fjm8
2026-10-13 16:13Z
cve.org record for CVE-2026-102989
cve_org · https://www.cve.org/CVERecord?id=CVE-2026-102989

this entry in the feed

GET /api/v1/feed/CVE-2026-102989

{
  "etk_id": "ETK-2026-261",
  "cve_id": "CVE-2026-102989",
  "display_id": "CVE-2026-102989",
  "ghsa_id": "GHSA-qx66-fv34-fjm8",
  "euvd_id": "EUVD-2026-98849",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Cross-site scripting in TanStack Start server functions",
  "summary": "Affected TanStack Start server-function packages can return attacker-controlled HTML from an application's origin. An unauthenticated attacker can target a server-function URL; exploitation requires a victim to open the crafted link, after which script may access same-origin data and act with that visitor's permissions.",
  "mitigation": "Upgrade @tanstack/start-server-core to 1.169.39, @tanstack/react-start to 1.168.60, @tanstack/solid-start to 1.168.57, or @tanstack/vue-start to 1.168.56, as applicable. Until upgraded, restrict requests to configured server-function paths with tested edge or WAF rules and apply a restrictive CSP to server-function responses.",
  "vendor": "npm",
  "product": "npm:@tanstack/start-server-core",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.143.12, < 1.169.39"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.169.39"
      ],
      "package_name": "@tanstack/start-server-core",
      "purl": "pkg:npm/@tanstack/start-server-core"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.143.12, < 1.168.60"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.168.60"
      ],
      "package_name": "@tanstack/react-start",
      "purl": "pkg:npm/@tanstack/react-start"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.143.12, < 1.168.57"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.168.57"
      ],
      "package_name": "@tanstack/solid-start",
      "purl": "pkg:npm/@tanstack/solid-start"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.143.12, < 1.168.56"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.168.56"
      ],
      "package_name": "@tanstack/vue-start",
      "purl": "pkg:npm/@tanstack/vue-start"
    }
  ],
  "cwes": [
    79
  ],
  "cvss_score": 9.3,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N",
  "epss_score": 0.0052,
  "epss_percentile": 0.4276,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": true,
  "check_confidence_basis": "mechanism_verified",
  "exploit": false,
  "pipeline_minutes": 21.752354033333333,
  "t0_at": "2026-10-13T16:13:13.105000+00:00",
  "signals": {
    "check": {
      "at": "2026-10-01T17:44:35.255263+00:00",
      "days": -11.936549186770833,
      "is_lower_bound": false,
      "measured_at": "2026-10-13T16:13:13.105000+00:00",
      "url": null
    },
    "trigger_signal": {
      "at": "2026-09-30T17:57:08+00:00",
      "days": -12.927836863425926,
      "is_lower_bound": false,
      "measured_at": "2026-10-13T16:13:13.105000+00:00",
      "url": "https://github.com/TanStack/router/security/advisories/GHSA-qx66-fv34-fjm8"
    }
  }
}

Anchor corroborated by the cve.org commit 3297e1a677d0.

published 2026-10-01 17:22Z
last change 2026-10-21 13:12Z

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