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 () or Data Mode (createBrowserRouter/). This issue has been fixed in version 7.18.0.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html
References
- https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180
- https://github.com/remix-run/react-router/commit/09e6020d1950e54f361f7ad00938ecd4dde60929
- https://github.com/remix-run/react-router/pull/15186
- https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0
- https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78
- https://github.com/remix-run/react-router/security/advisories/GHSA-chx6-hx7r-mcp5