Insufficient verification of data authenticity in React Router - CVE-2025-43865
Published: August 21, 2025
Vulnerability identifier: #VU114340
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-43865
CWE-ID: CWE-345
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to spoof contents and modify all the values.
The vulnerability exists due to it's possible to modify pre-rendered data by adding a header to the request. A remote attacker can modify pre-rendered data by adding a header to the request to spoof its contents and modify all the values.
Affected software
React Router
IBM Concert Software
watsonx.data
IBM Concert Software
watsonx.data
How to mitigate CVE-2025-43865
Install updates from vendor's website.
React Router - update to 7.5.2
IBM Concert Software - update to 2.0.0
watsonx.data - update to 2.2.1
IBM Concert Software - update to 2.0.0
watsonx.data - update to 2.2.1
External 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