CVE-2026-21884

React Router SSR XSS in ScrollRestoration

HIGH
8.2
CVSS Score
Published: January 10, 2026 at 02:41 AM UTC
Updated: July 15, 2026 at 02:18 AM UTC
3 products affected across 2 vendorsReact RouterRemix Run /reactReact Router

Using react-router by remix-run?

Get instant alerts when new vulnerabilities affect react-router - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.2
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.0.0 ≤ v ≤ 7.11.0
v < 2.17.3
Affected range stops below 2.17.3, so it looks safe — our inference, not a vendor statement
v < 2.17.3v < 7.12.0
Affected range stops below 2.17.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.12.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (8)

x_refsource_CONFIRMThird Party Advisory
Source: cverecord
https://github.com/remix-run/react-router/security/advisories/GHSA-8v8x-cx79-35w7
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:19712
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:3782
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:3958
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:3960
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-21884
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=2428421

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card