Description

React Router is a router for React. In versions on the 7.0 branch prior to version 7.5.2, it's possible to modify pre-rendered data by adding a header to the request. This allows to completely spoof its contents and modify all the values ​​of the data object passed to the HTML. This issue has been patched in version 7.5.2.

Classification

CVE ID: CVE-2025-43865

CVSS Base Severity: HIGH

CVSS Base Score: 8.2

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Affected Products

Vendor: remix-run

Product: react-router

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 4.4% (scored less or equal to compared to others)

EPSS Date: 2025-05-24 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: poc

SSVC Technical Impact: partial

SSVC Automatable: true

References

https://nvd.nist.gov/vuln/detail/CVE-2025-43865
https://github.com/remix-run/react-router/security/advisories/GHSA-cpj6-fhp6-mr6j
https://github.com/remix-run/react-router/commit/c84302972a152d851cf5dd859ff332b354b70111
https://github.com/remix-run/react-router/blob/e6c53a0130559b4a9bd47f9cf76ea5b08a69868a/packages/react-router/lib/server-runtime/routes.ts#L87

Timeline