Vulnerability in Remix-run React-router

CVE-2026-53666

React Router is a router for React. In versions 6.4.0 through 7.17.0, if application code was written in a way that allows attacker-supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for a…

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53666?
CVE-2026-53666 is a medium-severity vulnerability in Remix-run React-router, classified under Use of Externally-Controlled Input to Select Classes or Code (Unsafe Reflection). CVSS score: 6.1/10. Published 2026-07-27.
How severe is CVE-2026-53666?
Medium severity. CVSS v3 base score is 6.1 out of 10.