React Router: Unauthenticated Denial of Service via Inefficient Route Matching
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.7%
exploitation probability
0.7%top 50% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
remix-run · react-routerReferences
https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180https://github.com/remix-run/react-router/commit/09e6020d1950e54f361f7ad00938ecd4dde60929https://github.com/remix-run/react-router/pull/15186https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78https://github.com/remix-run/react-router/security/advisories/GHSA-chx6-hx7r-mcp5