CVE-2026-33244 | React Router has stored XSS via unescaped Location header in prerendered redirect HTML

React Router is a router for React. In versions 7.5.1 through 7.13.1, when using Framework Mode with pre-rendering enabled, improper neutralization of the HTTP `Location` header value can permit Cross-Site Scripting (XSS) in the statically generated HTML files if the redirect location comes from an untrusted source. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.13.2.

Published: 2026-06-02 Last update: 2026-06-03 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33244 is rated Low Risk (24.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). 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-2026-33244

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 2026-06-03 — 0.03% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33244

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
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.
 2.3 2.7 [email protected]

Weakness enumeration for CVE-2026-33244

GitHub Security Advisory for CVE-2026-33244

GHSA-f22v-gfqf-p8f3 · Severity: medium · Ecosystem: npm — React Router has stored XSS via unescaped Location header in prerendered redirect HTML

OS Trackers for CVE-2026-33244

vendor priority summary link
suse medium CVE-2026-33244 severity moderate: SUSE including 2 source package names (trento-web, velociraptor), 5 product×package rows across 3 product lines (SUSE Linux Enterprise Server 16.0, SUSE Linux Enterprise Server for SAP applications 16.0, openSUSE Leap 16.0): Known Not Affected 5. https://www.suse.com/security/cve/CVE-2026-33244/

Affected software / configurations for CVE-2026-33244

Vendor Product Version Raw CPE
shopify react-router >= 7.5.1, < 7.13.2 cpe:2.3:a:shopify:react-router:*:*:*:*:*:node.js:*:*

References for CVE-2026-33244

cvelogic Threat Intelligence