CVE-2025-43865 (CVSS 8.2)

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.

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CVSS v3.1 Score

8.2

HIGH

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

Weakness Type (CWE)

CWE-345 CWE-345

References

Other References

https://github.com/remix-run/react-router/blob/e6c53a0130559b4a9bd47f9cf76ea5b08a69868a/packages/react-router/lib/server-runtime/routes.ts#L87 https://github.com/remix-run/react-router/commit/c84302972a152d851cf5dd859ff332b354b70111 https://github.com/remix-run/react-router/security/advisories/GHSA-cpj6-fhp6-mr6j

Frequently Asked Questions

What is CVE-2025-43865? +

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. It has a CVSS v3.1 base score of 8.2 (HIGH).

How severe is CVE-2025-43865? +

CVE-2025-43865 has a CVSS v3.1 score of 8.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2025-43865? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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