Resource exhaustion in Remix-Run React-Router
CVE-2026-55685
React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7.18.0.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.004 (33.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Remix-run React-router — versions >= 7.0.0, < 7.18.0
- Shopify React-router
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- 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-2026-55685?
- CVE-2026-55685 is a high-severity vulnerability in Remix-Run React-Router, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-27.
- How severe is CVE-2026-55685?
- High severity. CVSS v3 base score is 7.5 out of 10.