CVE-2026-21884 | React Router SSR XSS in ScrollRestoration

React Router is a router for React. In @remix-run/react version prior to 2.17.3. and react-router 7.0.0 through 7.11.0, a XSS vulnerability exists in in React Router's <ScrollRestoration> API in Framework Mode when using the getKey/storageKey props during Server-Side Rendering which could allow arbitrary JavaScript execution during SSR if untrusted content is used to generate the keys. There is no impact if server-side rendering in Framework Mode is disabled, or if Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>) is being used. This issue has been patched in @remix-run/react version 2.17.3 and react-router version 7.12.0.

Published: 2026-01-10 Last update: 2026-01-30 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-21884 is rated Low Risk (37.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21884

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-10 — 0.04% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21884

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 4.7 [email protected]

Weakness enumeration for CVE-2026-21884

GitHub Security Advisory for CVE-2026-21884

GHSA-8v8x-cx79-35w7 · Severity: high · Ecosystem: npm — React Router SSR XSS in ScrollRestoration

OS Trackers for CVE-2026-21884

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2026-21884
suse high CVE-2026-21884 severity important: SUSE including 3 source package names (firewalld-prometheus-config, golang-github-prometheus-prometheus, velociraptor), 11 product×package rows across 8 product lines (SUSE Linux Enterprise Module for Package Hub 15 SP7, SUSE Linux Enterprise Server 16.0, … (8 product lines)): Known Not Affected 11. https://www.suse.com/security/cve/CVE-2026-21884/

Affected software / configurations for CVE-2026-21884

Vendor Product Version Raw CPE
shopify react-router >= 7.0.0, <= 7.11.0 cpe:2.3:a:shopify:react-router:*:*:*:*:*:node.js:*:*
shopify remix-run\/react < 2.17.3 cpe:2.3:a:shopify:remix-run\/react:*:*:*:*:*:node.js:*:*

References for CVE-2026-21884

cvelogic Threat Intelligence