XSS in Remix-Run React-Router
CVE-2026-53667
React Router is a router for React. In versions 7.11.0 through 7.17.0, the RSCErrorHandler is missing protocol validation, allowing for redirects from untrusted sources. This issue is a follow up to CVE-2026-53667, and only affects consuming applications if they are using the unstable RSC APIs. This issue has been fixed in version 7.18.0.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (10.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N.
Affected products
- Remix-run React-router — versions >= 7.11.0, < 7.18.0
- Shopify React-router
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-53667?
- CVE-2026-53667 is a medium-severity vulnerability in Remix-Run React-Router, classified under Cross-site Scripting. CVSS score: 6.9/10. Published 2026-07-27.
- How severe is CVE-2026-53667?
- Medium severity. CVSS v3 base score is 6.9 out of 10.